I am going to sound like a MS fan girl but I love Windows 7 HomeGroup. One of the irritating things about my Mini (which is used daily mostly from my coffee table) was having to send myself email attachments or moving things to my desktop via a USB stick to print. Also, neither really helped if I wanted to print a web page. It didn't work at all of course if I needed something from my desktop.
HomeGroup was sooo easy to set up. The instructions seemed a little confusing at first, but after checking out a couple of walkthroughs it was straightforward when it came time to actually go through the steps. I had some concerns about being able to share one of my printers as one is an old HP LaserJet with a Jet Direct (network) card plugged into my router. HomeGroup was smart enough to tell my Mini it needed some drivers, installed them itself and it worked.
No more \\computername no more ping x.x.x.x, running nbstat and no more fiddling with NetBIOS or TCP/IP mapping.
What MS says: You can join a homegroup in any edition of Windows 7, but you can only create one in Home Premium, Professional, Ultimate, or Enterprise.