Chris,
teaming them together is a great idea, except you can't put the same IP on two different NICS. How would you point clients to the other nic?
If you can figure out how to point clients to the other nic in the even of a failure I would assign all websites to "All Addresses" and use host headers to difereniate (sp) the sites.
On another note, NICs failing does happen, but if your server is where you can get to it and you have something that can monitor the nics, putting two nics in a server is kind of pointless because you can get to it and replace the NIC easily.
Also, If your server is in a remote data center then what I would do (or rather what I did) was to have two seperate NICs in each server, if NIC one fails, I can remote in using the other nic, and move the IPs over the the working nic.
It works but it's not automatic.