Well, I'd say GMA950 should work better than poulsbo, and the driver is open source and all features should be supported. However, some say it's a PITA to get working, some say it's too slow for them. I don't have experience of it, but I know Intel driver support for older gpus is not that good as it is for newer ones. So, it might not be fast enough for Gnome3, Unity and other nonsense like that (?), but it should run any sane desktop just fine.

This all said, I have a laptop with ATI MACH64 4MB and it runs dwm fine and manages to somewhat handle internet browsing fullscreen at 1027x768, so something being fast or not is highly subjective. If you do a google search, there's plenty of satisfied ideapad users running linux. You might need to try few distros to see what runs properly, and generally you should just forget Gnome/Unity/KDE on such hardware, and go lightweight. So, Arch and Crunchbang, and also lighter Ubuntu variants like Lubuntu, are probably what you want to try with it. Also, there's a boatload of distros out there for netbooks with varying system requirements, so you might want to look at those too.