Yes. There is development in four areas: computer design, material science, features, and finally a category I'm going to call "not better just different".
Lens design has always been a mix of art and science. In the first part of the previous century, art was clearly primary (even for scientific lens designers). Now, lens design software shifts the balance towards science. There's certainly still art involved in making a lens with pleasing rendering, but the science sure helps. Every lens is a compromise between different constraints: optical (aberrations, sharpness, telecentricity, zoom, parafocal vs.varifocal), physical (number of elements, size and weight), and cost (type of elements used, build quality, complication). Software helps designers create a lens within predetermined acceptable criteria, and it lets them test that lens using simulation before spending a lot of money to determine if the concepts are sound.
This software follows both general improvements in the design software (as one might see improvements in Photoshop or in any CAD program), and developments in the fields of optics and photonics. The same advances in computational photography that enable the Lytro light-field camera help out here. And these advances in software in turn are reflected in the modern lens designs created this way.
I'm going to lump improvements in manufacturing in with this category; maybe it deserves its own. Modern manufacturing techniques use computerized machinery to reliably produce complicated individual lens elements, making their use less expensive where they might have been prohibitively costly before.
There are three big areas where this is important.
First, the glass. Different compositions of glass have different optical properties, with varying desirability for photographic lenses — for example, low refractive index, low dispersion, and high light transmittance are all good. Many of the old ways of making glass with desirable properties were quite expensive or have other serious drawbacks. Advances in material science have produced glass with similar properties without those downsides. It's likely this will continue to be the case.
Second, the coatings on the lenses have improved. These are used on all good lenses to reduce glare, which is very important because stray light bouncing around reduces image quality. Newer coatings do this better, more cheaply, and have other desirable properties like repelling fingerprints and dust.
And third: plastics! We're not at the point where plastic elements can replace glass in anything but toy lenses, but plastic is used increasingly in lens construction where metal would be before. In some cases, this is just to make them cheaper with no concern for quality, but when good plastics are used well, they can make a lens lighter and smaller with no compromise to build quality.
I'm going to highlight image stabilization, since that's the obvious one. Modern lenses can offer up to five stops of benefit from stabilization — that is, shutter speeds of up 32× longer with the same sharpness. And newer advances in IS correct for more complicated and different types of movement. Since competition here is fierce and there are a lot of ideas still untapped, expect this area to continue to improve rapidly.
As bokeh — the visual quality of the out-of-focus areas — has become an increasingly important factor, a higher number of a aperture blades and blades with rounded edges are more common. This feature has been available for a long time on premium portrait-lens designs, but now it seems to be almost a must-have feature even on a lower-end "nifty fifty", like those from Nikon and Pentax.
Another example is better in-lens motors, using ring-type ultrasonic designs. And yet another example is the clutch mechanism in newer Pentax lenses, which allows full-time manual focus even with body-driven autofocus. Or, some Pentax lenses have a clever built-in/pull-out lens hoood. This isn't anything to do with optical design, but is an example of practical innovation which is really beneficial to the photographer.
Weather-sealing is another feature: there's nothing particularly innovative about that (except some of the material science, perhaps), but fitting it into more lens designs is progress.
As there's more convergence between video and still photography, we'll see some more changes related to that: more silent operation, and stepless aperture settings (rather than being limited to the traditional stops or predetermined fractions thereof; this allows smooth changes while filming without causing jumps in exposure). Arguably many of these features fall into the next category when viewed from the non-video perspective, as for example stepless aperture isn't really a feature with a lot of benefit for still photography.
Not Better, Just Different
In this category: changes made to benefit digital, and new designs for smaller sensors.
For digital, designs need to take into account the increased reflectance of sensor material over film. This means that there's more stray light bounced back into the lens than there was before. Additionally, most sensors are less forgiving of light that isn't coming from straight-on, making telecentric design more important.
And, smaller sensors simply means that lenses can be designed with a smaller image circle, or at least with those important properties only optimized for the center without worrying so much about what would be the corners on full-frame. This allows smaller, lighter, and cheaper designs which still offer excellent image quality — Pentax's DA Limited series being the poster-child here, with the smc DA 15mm f/4 ED AL Limited being an example of a recent innovative lens design which incorporates many of the things I've listed above.
There's another change which could be put in this category as well. Many cameras now offer automatic software correction of lens defects like chromatic aberration and barrel distortion. In fact, in some point & shoot and compact interchangeable lens cameras, this isn't even optional — it's just on. The camera communicates electronically with the lens and "knows" how to adjust the image in RAW processing in order to compensate for that lens model's particular quirks. This allows the compromise parameters for the lens design to be different: those factors which can easily be corrected for in software can be left to go wild, and other desired characteristics taken beyond what they could be otherwise. Right now, the focus is mainly on size, weight, and cost, but as image processing gets faster and better, it won't be too surprising to see this thinking come into high-end designs as well.