For the lag you'll have no problem, but for the graphic card I can't tell you as you didn't mention the model.
I run the wotlk client 3.1.3 but it still work on TBC servers, without northrend. I do believe the system requirement won't go up once they open northrend. So my game run smoothly on a core duo 1.6ghz and an low end ATI 2400, with all settings on medium except shadows who are on the lowest setting.
If you have an integrated Intel GMA there isn't much you can do, I guess with full low settings you get 25fps at best and in the major cities it must lag badly at <10fps.
When you log on a realm type "/join english
" to get in touch with the community members.
WoW English/Chinese glossary
(2000+ translated words) found on wow-in-chinese.jfs-web.chEnglish speakers are consolidating on the same realm for Cataclysm check this thread