They also announced the Exynos 5250, A15 cores and Mali T604 (2x-5x faster than Mali 400).
Samsung has in house silicon production so things happen faster but this will likely have to wait for SGS4.
This graph illustrates well why I am willing to wait till summer, sizable leap in performance expected. Not entirely convinced the 28nm die will ship in volumes by then. Either way, whoever get's his hands on the first phone to ship with a 28nm, ARM A15 SoC with one of the next gen GPU's can rest assured that his phone will remain competitive for a very long time.

Back on topic, two good phones back to back but a Nexus subsidy would really help with retention. My contract for the HD2 expires in March, I would be willing to wait til summer for the 3 choices:
1. Switch to Sprint for the next Evo, now that they are serious about LTE.
2. Port my number to GV, buy a kick ass phone out of contract and sign up for Straight Talk $45 unlimited plan, they use AT&T's HSPA+ network.
3. Buy a good T-mobile phone in the summer, if they land one. Or maybe by some luck I find one one my own with AWS bands on board.
T-Mobile is finishing the year with nice phones, let's hope they start the next one the same way. I would like to extend the contract and hoping they give me the incentive.