There are some small efforts, but I'd rather have formal methods from the beginning, not as an afterthought.
The problem is that market forces favor releasing early rather than releasing correct things. It's the MIT vs NJ paradox again, or worse is better. But this time the potential risks are much bigger.
solidity, etc sure maybe... but at that point, releasing early is probably a good thing so that you can get a whole community working on things and getting ideas and collaboration from a large group of people
*edit: unless you mean like geth, or some minimal reference client should be formally proven
There are more agile options. For example, model checking all protocols is pretty easy in comparison to theorem proving. Still a significant effort, but perhaps an order of magnitude easier.
Just because a bridge is still standing today doesn't mean it's safe. Ethereum has been almost religious in violating best practice blockchain design.
The sharding stuff, however, is still iffy at the moment (I've studied it pretty closely) ...but if vitalik is confident he can make it work, I'll bet on v every time.