It's interesting that the predicted requirements only ask for a 512 MB graphics card. I was under the impression that it was hard to buy a new computer with less than 1GB. Seems strange if this isn't being utilised?
Ignore those predicted requirements. It's generic requirements that are not specific to skyrim, and the resolution of your display makes a lot more difference.
In general however, most recent 2010-2011 games are playable at high settings on laptops at 1920x1080 resolution with a 1GB NVIDIA 460m, 555m, AMD 5830m or similar card.
If your monitor or laptop display is very low resolution like 1280x720, which is standard for PS3 and XBox360, then you can get by with a much weaker card.