I can't believe there isn't already a thread about this, but I couldn't find it (even posted in the help me find it thread).
Any BB you trade in that doesn't have a cracked screen or water damage and is in overall good condition (these sell for 20 online) is worth 200 in credit for a new smart phone 250 for a new BB. Any credit not spent goes to pay acct balance.
I have no idea when this is over, rumors have been flying to as soon as tomorrow but if you can get ahold of these phones fast it would be worth nearly 1000 bucks on a 5 line plan!!