Unfortunately you picked a very bad night to download. This is the last day that people can redeem their $20 credit so the server traffic is likely very large. The store has been buggy all day because of it (or so I'm assuming).
Also if you are not using a browser that has an internal download manager like Firefox that should be something to try.
If you are dead set on IE then my friend scook has recommended freedownloadmanager to me and others quite a few times... and that dude is like all smart and stuff.
Cheers and I hope you enjoy X2 once you actually get it onto your system.