Upgrade from SL to ML

I have an early 2008 iMac (2.8Ghz Core2Duo), 4 Gb of RAM running SL. I've been wanting to upgrade to ML but, where I believe my processor is more than fast enough to run ML, I'm a bit worried about the 4Gb of RAM not being enough.

My mac can hold 6Gb (whereas there's only 4Gb officially supported) but it seems that it's not always ideal (loss of dual-channel speed, system instability, ...).

I use my Mac for iWork, iTunes, iPhoto, some iMovie from time to time, browsing the web, play some occasional games (things like Half Life 2, Team Fortress on Steam, Minecraft, etc.) and other light-weight apps like Bento and some stuff running in the background like Google drive, Dropbox, Found, etc (so nothing fancy like Creative Suite or anything like that).

So, bottom line, 4Gb ok or better hold out and wait until I get a new Mac next year ?