Throttling replication

[Mark]

 Is there any way or forthcoming patch that would allow configuration 
of how much network bandwith (and ultimately disk I/O) a slave is 
allowed during replication? We have the current problem of while 
replicating our disk I/O goes through the roof. I would much rather have 
the replication take 2x as long with half the disk I/O? Any thoughts?

Thanks