There had been hints of it before, but now we’re seeing the first signs of BlackBerry Internet Service 3.1 coming to life, featuring Yahoo! and Windows Live Hotmail contact sync. I’m not seeing anything up on Rogers right now, but some folks have had new icons pushed to their device, and new options enabled in e-mail setup. Right now Yahoo! contact sync is the only feature shown in the official BIS 3.1 doc, so Hotmail sync for BlackBerry may be pushed off until the next update, likely once Wave 4 gets all settled in.
The last BIS upgrade included OpenOffice file support and was quickly followed up with two-way GMail read/unread status syncing. There’s still no sign of a BIS-side Calendar sync for Google, Microsoft, or Yahoo!’s respective services, though GMail does have a separate app that syncs up Calendar and Contacts already.
Be careful about syncing contacts through Hotmail, when it does come around – when I made the switch to GMail, I imported everything, then used Google Sync to get them all on my BlackBerry. Little did I recall that about 90% of the people imported included MSN contacts from 1998, and had a hell of a cleanup job to do.