Did buy a Nexus One; have now had it for an hour or so. The following is not a review, but some observations:
- It will work without a SIM card from the start. So if you want a gratuitously expensive wifi PDA...
- The Google Account-based functionality (e.g. application Market, contacts sync) requires a Gmail account - and any Google Account with Gmail necessarily has the Gmail address as its primary email address. (Since Gmail lets you forward to another address, this doesn't matter unless you use Google services that send mail on your behalf, such as calendar invites.) I haven't tested whether they will still work if you then remove Gmail (but I would note that if it's possible at all, having a Wave account might help, since that seems to allocate a no-@-sign 'username' in the same way Gmail does).
- Not perfect, but mighty slick. Need to stop playing around and get some sleep.