The shutter mechanism is one of the few mechanical components on a DSLR(other than hinges, seals, buttons, dials). The Shutter mechanism is the second most complicated part of a DSLR after than the sensor. If replaced properly, by the authorised service centre, It will almost breathe new life into your DSLR. Do not worry about the technological obsolescence of your DSLR.
Based on your name, I am assuming you are from India. So, in India, finding a good used DSLR(better model than the one you have) with low shutter count is going to be far more expensive than just replacing the shutter mechanism. As long as the main and command dials and D-Pad are working fine, replacing your shutter is going to almost renew the life of your camera. The sensor does not wear out(unless you are doing astro-photography and star trails, in which case hotspots and burnt pixels become far more common and you can consider the sensor to be wearing out).
Look at pro tog cheap camera challenge by DRTV. You don't need the latest and greatest DSLR for great pics but your DSLR definitely needs a shutter to be able to take pics.
So, I would say If your DSLR shutter life has reached the rated life, GET IT REPLACED IMMEDIATELY. There is no need to go out and buy a new camera but get it replaced ASAP. a torn shutter/broken mechanism can damage the sensor which will be a real nightmare(DSLR is rendered useless, resale value will crash making it even more difficult for you to upgrade if you want to/need to).
YOU CAN EXPECT TO SUE THE CAMERA CLOSE TO THE NEW SHUTTER's LIFE(depends on the condition of the dials and buttons).