Windows 7, question about 32 bit, 64bit...help needed

I have vista home premium 32bit and was wondering if windows 7 comes with both a 32bit disc and 64bit disc. I recently pre ordered it, home premium version, but I am unsure if I need to update my system now, or if I can just do an install of 64bit when my windows 7 comes? And, if I have to do the upgrade now, any idea of the cost to get 64bit? When I talked to dell they tried to sell it to me but I never heard the price and wanted to check if my Windows 7 upgrade will come with that option to go 64bit? Any help would be appreciated. Thanks

thank you very much for your help... i guess i'll just wait until windows 7 arrives and do the clean install. I got it on that early preorder deal for like 58 dollars, otherwise I wouldn't have gotten it at all...heres to hoping its better

thank you very much for your help... i guess i'll just wait until windows 7 arrives and do the clean install. I got it on that early preorder deal for like 58 dollars, otherwise I wouldn't have gotten it at all...heres to hoping its better

theMAINEevent33