I about went with the N900 when it was first released because I really like Nokia's hardware and never cared much for Symbian touchscreen devices so with the N900 running Maemo it looked really interesting. I really like the slide out keyboard and hear nothing but good things about the browser. I know a lot of apps were moved from the previous Nokia internet tablet but I don't think their are as many as with Android.
It just really depends on what you want, I think Android is probably a better bet for now but Maemo is really interesting and I think some good phones will be coming next year if they keep on developing the operating system. I don't think you can really go wrong with either to be honest.
The handset running a full version of firefox is just plain awesome, can't wait till fx is out for Android.