Ports between 360 and PS3 are never going to end, it just makes good business sense. It's not that different from last generation - the only difference is a few PS3 exclusives were ported to 360 after publishers realized it wasn't so popular after all. PS2/PSP/Wii ports are also here to stay, but PS2 will be phased out over time...probably all but gone by Christmas 2008.
Old games getting remade on new systems? I think we'll continue to see these on Wii into next year, because a lot of publishers are trying to play catch-up on the system. Again, I'd say they'll be pretty much gone by the end of 2008. I don't think it's that much of an issue on PS3 and 360...you've got Ninja Gaiden Sigma and Bully, and there were a few more at the Xbox 360 launch, but it's not that common.
