PokeCommunity doesn't host ROMs, nor does it allow the distribution of them from here, so ROM hacks would not be playable directly on the site. Also games from the Game Development forum would probably take up a lot of bandwidth or what not, so it would only be viable if they were made available to Supporters of a certain level. Though that'd bring up the problem of Copyright and Fair Use.
I wouldn't really support games on PokeCommunity myself as there isn't really any point. If you want to play a quick Flash game or what not, there are plenty of other places online in which you can do so already. In the end though, it's up to the higher staff whether or not they want to implement this, something similar, or nothing at all.
1. I used to play games on Facebook, but not any more
4. I'd probably poke around in it every now in then
5. RPGs (Like Pokemon)