Yeah,, neither look like they're going to stop anytime soon. The only thing which may go against Murili is his action. I mean, when I look at the bend, it seems pretty big. I mean, if it's legal then thats great, but if not something must be done. If they were to say test himin match conditions and find out he's going over the limit.
One thing is Murili's favor is that the rest of the Sri Lankan side isn't terribly letal with the ball (well they have Malinga now, whos bowl everyhting short or full experiment worked pretty well), so he ends up doing heaps of bowling and has pleanty of wickets to claim. If there was say a Bond in his side, he may have to share the wicket tally around a bit more.
The Aussie side will never use Warne as much as SL use Murili, despite the Aussies playing MUCH more tests. I guess it evens out.