Remember that 10, 100 and 1000 were theoretical maximums. I.e. under perfect conditions you will achieve these speeds, but most of us don't live in a static lab setting with perfect conditions.
You should get more than 10, but if your cards are 10/100, you will probubly not reach 100. I would expect speeds around the 60-70 mark at best.
For file transfer between machines and gaming, on the local network this is important. For things like DSL/Cable/High Speed it doesn't matter because the high speed comes in at a speed slower than 10.