I'm not one to speculate, but I reckon a little rain dancing might be taking place in Red Bull's Milton Keynes factory as we near the Spanish F1 Grand Prix.
I've even heard through the grapevine that British customs reported a notable rise in the number of Native Americans entering England, bound for Milton Keynes.
Malaysia (Webber 6th but was moving up the field when the rain came) and Shanghai (Vettel 1st, Webber 2nd) demonstrated that the Bulls are superior handling cars in wet weather, due in most part to their impressive levels of mechanical grip. Jenson Button was even quoted saying that "he couldn't get near the Red Bulls in the wet".
In the short term, this means Red Bull's results are likely to be good in races that end up being reasonably wet.
Even better news for Red Bull is that mechanical grip is harder for teams to improve upon than aero grip. Unlike aero grip—where new parts can be bolted on willy-nilly—mechanical grip is derived from the car's chassis and suspension. Improvements require wholesale changes to the car's structure.
In short, Red Bull's relative advantage should remain for quite a few races.
Add to the mix a double-decker diffuser, combined with a few other bits of Newey brilliance, and Red Bull may start to give Brawn trouble in the not-so-wet races.