If you run a tor relay you can hide your own traffic in the noise.
Assuming you don't have way more traffic than noise.
I believe a global passive adversary can easily use timing attacks to deanonymize tor.
I myself don't want to live in a world where you need to actively hide from huge adversaries. I'd prefer a more careless world with smaller adversaries. Hopefully, widespread adoption of Bitcoin will take a lot of power from governments, so we won't have massive money wasting TLAs that create misery all around the world.
Edit: I meant "don't want to live", not "don't live".
Let's work this out though. What do we know about the NSA programs?
1. They collect metadata on packets originating from computers connected to pretty much all the US ISPs and many other countries' ISPs.
2. The list of Tor entry and exit nodes is public and you can bet your ass the NSA knows what this list is at all points in their logging history.
3. Most websites are based in the US, and so it's highly likely that the paths from the Tor exit nodes to these websites have some intermediate point on which traffic is logged by the NSA.
4. The NSA has access to a large training dataset of how traffic entering and leaving the Tor network looks because a whole bunch of federal authorities use Tor.
Given 1-4, I think it's likely trivial for the NSA to train a learning algorithm that will correlate packets leaving a Tor exit node with those entering an entry node.
They probably can't do this all the time because it is more expensive than just a database lookup like in the unencrypted case, but it seems me to that if they had the motivation to get you, it wouldn't be too hard for them.