Blizzard has always been pretty good about making sure everyone who wants to play there game can. The majority of your specs are right on for playing a MMO, except the videocard. Also, A lot of video options can be disabled through their video options. Here are some of the issues you will have playing WoW on your laptop, however, if you can get it to run...
Choppy Graphics.
MMO's are a dynamically changing world, with other people walking around and interacting in addition to the world itself. As soon as you find yourself surrounded by other players, that's more models that need to be loaded into video RAM and system ram as you play. The on board solution you have shares the RAM with you system, and is going to gag on this every time it overflows. If you attempt to give the videoard more RAM to se, it will gaga when the system RAM overflows and hits the paging file... painful indeed.
Minimalist Graphics
In addition to the problem above, you will have to turn down all of the graphic settings to make the game run "smoothly". Basically everything will be set to low, low, low none, none, none, etc just to make the game semi-playable.
To give you an idea, I can barely play on my laptop from school (Back home for the holidays) and have to use minimalist graphics, on a much better system. I'm running a 3.2GHz Intel, Nvidia GeForceFX Go5700 w/ 64MB of RAM, 512MB DDR, and 80GB HD with a 1.2GB Paging file (because 512 isn't enough for WoW, damn that Ironforge!!)
In my opinion as a game designer and gaming experience with WoW on a laptop, I really don't think you will have an enjoyable experience on your current laptop system. I'm sorry
