I have a MacBook Pro Mid 2012 (non retina) which was my first MBP and I love it but seeing the retina version i've been meaning to upgrade my laptop. Is it worth upgrading now or is there a expected new release this year? Also what would be a ideal selling cost of my current MBP Pro in the UK? Model: MacBook Pro (15-inch Mid-2012) CPU: Intel Core i7-3720QM Memory: 16.00 GB (2x 8GB Crucial) Hard Drive: Samsung 830 256GB SSD Graphics: Intel HD Graphics 4000, NVIDIA GeForce GT 650M Original box, as new magsafe adapter incl Minor dent on the right side of the trackpad but other then that spotless. Thanks!