Much of this will depend on what specs the D7000's SD card slot supports. There are MUCH faster SD cards in the works (SDXC and UHS-1)which could top 100MB/s.

I have several of the Sandisk 30MB/s cards and I would think if you need high speed write abilities (like mashing down RAW at 6fps for a while) having both banks filled with those cards should suffice as long as you have the banks set to split the files.

Doug
D300s | MB-D10 | SB-700