Play for achievements (or just for fun).
If you've yet to earn your 7 on the 7th Vidmaster achievement, now's the time. August's 7 on the 7th is live and stuffed full of your community maps. There's no Recon being awarded this time out, but you'll need to snag this achievement if you want to earn it eventually (9/22/09 - Halo 3: ODST in all stores, everywhere). And of course, if you just want to play to be entertained, you're more than welcome to do that too.
Go. Play.