I've used a huge variety of Mac models since 1987 and I LOVE the Mini.
Sorry, I misquoted the processor; it's 2.0 GHz.
You can put 3GB memory in it by mismatching DIMMs.... one slot carries 2 GB and the other carries 1 GB. Works great.
I was also concerned about the published 2GB limit but this is based on using matched-pair DIMMs. The guys at OtherWorld Computing (OWC) convinced me of their results using mismatched memory cards.
Mini memory upgrade info here(scroll down to the bottom for the 3GB set)
NOTE: upgrading a Mini is not for the impatient or the faint of heart. OWC has a video that shows how to do it. But the video makes it look easy... It's not. Make sure to have at least two very thin putty knives on hand, and don't plan on having your case come through in pristine condition. (You'll see what I mean.)
I have had zero trouble with this machine. It has everything I need and I am thrilled at the low cost.
I often run Lightroom, Bridge and Photoshop CS3 simultaneously and couldn't be happier with the performance. (That said, I'm also a freak for system and application optimization.)
Using a single LaCie 319 display, which I also love. I used dual displays for many years and I am very happy to be back on one with the latest apps from Adobe.
And several external FireWire and USB 2 drives.
If I win the Lottery (which I don't play) of course I would by a loaded Mac Pro and Eizo displays.
But for my money, this system really rocks.