Isn't it just a strait 1000 per war rank? 

I know that they come in a semi consistant flow.  It does seem that capturing extra flags make's it go up exponentualy faster, but I think that can be expalined at lets say 'X"war rank a second per flag. If you hold a flag, it isn't just exra war rank for you, it is deminished war rank for your oponent.

On the 2v2 map there are 9 flags, you each start with 3, and there are 3 neutral ones.  IF you hold all but the 3 your oponent started with, then your war rank is going up 2x as fast. ie. 60 WR/sec vs. 30 WR/sec

I'm pretty sure you get an extra bonus if you control a certain % of the flags, as well.  I think Frogboy said it at one point.

I'm pretty sure 10,000 is not rank 10.  I haven't checked specifically but if I'm not mistaken you hit rank 8 around 5000 or 6000.

The table:

0..........Rank 1
810......Rank 2
1620....Rank 3
2430....Rank 4
3240....Rank 5
4050....Rank 6
4860....Rank 7
5670....Rank 8
6480....Rank 9
7290....Rank 10

Plagerised from Dalzk's excellent forum post, credit were credit is due. He has suffered enough as a Liverpool fan.