It should run with no problems, I have a T420 with a QM67 chipset & Intel 3000 graphics. On the Lenovo website it says it's not supported - but it works. I've had mine running for over 2 years. I can't remember about the drivers, I think most of the drivers were picked up during installation with only the Wifi missing. The drivers that are missing/updated you can go on the Intel website and download the Wifi, graphics seperately or you can use the Win7/Vista drivers from the Lenovo site (Bluetooth springs to mind). The sound adapter I think I downloaded seperately, mine is a Conexant 20672 SmartAudioHD.
If this is your only machine I would make a recoverable disk image just in case and it might be a good idea you get the drivers first while you have an internet connection.