I just made the jump myself from a MBP late 2009 to a MacMini Server. It's on the way now. I hate having my laptop double as the desktop computer, media server, etc... I've got all these cables hanging out of it to connect it to 2 RAID drives, external monitor, etc... My hackintosh just died so it was time to look for a desktop/server replacement and use my MBP solely for mobile use.
If I were you, just upgrade the HD to a SSD and add some more ram if possible. That's what I did with mine and it still runs fine.
I put a 128GB SSD drive. Unfortunately, 2GB of RAM is the highest amount of ram you can put on it. But it's doing it's new job fantastically well. I am just waiting till the Mac Mini arrives.