My processor is the 1.6 Ghz Intel Atom.  All the winds are the same except for battery and wireless options.  Mine happens to be a U100-279US. I have same proc, RAM, chipset, and graphics as antechinus.  Also, I upgraded (or not depending on your point of view) the XP that came with it to Vista.  These little machines are surprisingly capable.  The wind also makes a nice hackintosh, as I am posting from it in OSX right now.  

The RAM upgrade really would help though as it would allow the integrated graphics to pull more system memory for graphics use.  I plan on popping an extra gig into mine at some point.  Unfortunately it does require taking off the entire bottom as there is no RAM access door.  

I play the sims2 on my wind U100.  I have the base game, Uni, Nightlife, Pets, Seasons, Free Time, and the Ikea stuff pack.  I have a rather large download folder full of awesome hacks and various assorted custom content.  I am also using clean templates.  I play with details and textures high (I like my sims to have all their fingers) and most everything else low.  It runs native resolution (1024x600) fairly well, and even runs to my 20" external monitor 1280x800.  On the external is gets a big slideshowy on the faster speeds, but on the smaller resolution of the wind itself, it runs fairly smooth.  I haven't upgraded my RAM yet either, and this is all with just 1 gig of RAM and on Vista.  If you have 2 gig of RAM and are running over XP, you will get even better performance.  I can load pretty big lots, including the downtown clubs and such.  It's not the smoothest thing in the world, but it works.  Be sure to grab the latest bios 1.09, which allows overclocking.  I overclock 15% when I'm playing on the external monitor to help it keep up.  The bios allows up to 24% overclock, but I haven't tried more than 15% yet.  For more info about the new bios, check the wind forums.