There are still people using and releasing things in VX, not to mention other "obsolete" makers: RM2k/3 and XP. In the end, if your game is any good, the maker you used won't matter that much. That said, it might be a good idea to move up to using VX Ace, eventually.
2k and 2k3 are probably the only 'obsolete' makers. XP, VX, and VXA are all widely used and are not obsolete yet. VX is still completely useable, so don't feel like your game is inferior because of it's engine.