Only for websites, not webapps.
There are not many computers left with 1024x786, so why still support it?
That entirely depends on your user base, for a commercial site I work on 1024x768 represents 9.49% (166,453) of our visitors, we will continue to support that for some time.
The flip side to that, a hobby project that I work on has a different audience and I don't support 1024x768 as it only represents about 2%.
Check your existing stats and use that to make the decision. Failing that create a responsive layout and stop worrying about the resolution.