Just remember that one thing the minimum requirements don't mention is that the resolution (At this point in time) needs to be 1024x768 minimum. There are ways around it, but if you can spend a few more dollars and not have to worry about it or wait for a UI mod, then why worry?
Just know that one of the main problems with the launch of the game, the out of memory crashes, can still occur. I have to watch my task manager to make sure Elemental isn't approaching the limit when I play. If it gets to 1.5G then I save, close, and reload. And the bigger the map, the faster it crashes. I run Windows 7, 2GB DDR2 (400mhz </3), Core 2 Quad 2.33ghz. Once the map gets fleshed out with AI, the game slows down. I'm sure this has something to do with the memory issues, as I also play Civ V and have a much lessened slowdown with the turns.
As most people have said, it's around 1.7+ gigs that the game typically crashes. Sometimes on larger maps I can only get two or three turns before saving and reloading, other times I can get almost to the end of a game. I played a multiplayer game against an AI, was kicking the tar out of it (I mean, it's simple stuff right now, fighting that AI), and I didn't get an OOM until around turn 400. Other times I'll be on a small 1v1 and get it around turn 200.
You may want to wait until 1.1 comes out as well just to see what happens in regards to these issues. I bought the collector's edition and while I like the game and can't wait to see the full concept realized, it's still being worked on.
On the other hand if you get it now, you can jump into the discussions and help Stardock make it the game we want, since they tend to take our suggestions seriously or at least consider the better ones.