This is a really good deal if you're after a PS3 and have a mobile contract about to run out and up for renewal. So long as you like Orange and can port your number you'll get a decent phone and an amazing games console which is worth over £399.
I spoke to Dial-a-phone about this as I was interested to see if they could match the deal with an O2 contract but they were amazed at the deal and said they'll probably sell like hot-cakes!
Should add, you don't need to port your number but it's handy if you want to keep your phone number the same. You can sign up for a deal and get a new number if desired.