If history is a guide the next Nexus will be available this year, but won't come subsidized with a contract till next year (for AT&T). Only wait for the next Nexus if you afford to spend $600+.
Well whats the resale value of a used nexus S 4 months from now. If i can get ~400 for it, then ill be spending 200 for the new nexus and will have a decent phone in the meantime.
The stock experience and a reliable phone is what im after. Coming from a captivate, its been hit or miss.
The phone is crap without a custom rom. The first one i owned was great, but eventually started having problems after about 8 or 9 months. Since then I have been through about 4 different captivates and all have weird problems. Not mentioning the GPS.
So although the SGS2 looks awesome on paper, Id take a nexus phone with slightly worse specs, since i would know its better quality - even though the nexus S is made by samsung........