Latte is perfectly capable of processing tasks like physics, it's been confirmed to have GPGPU functionality. That's partly what Latte is for and partly why all 3 platform holders have opted for a similar architecture.
Double precision floating point work this gen isn't going to be done by the CPU the way it was last gen.
As for the RAM you'll find developers happier dealing with the DDR3 and ESRAM/eDRAM combination than GDDR5 due to the former having considerably less latency and leaving developers with less idle clock cycles. Latency always has been and always will be more important than bandwidth.
And porting really won't be a problem for reasons I've already given.







