Do you have the source released somewhere? I'm interested in Rust but haven't really written anything large - I would find it interesting to see what a large project looks like, especially the kinds of problems that come up (like you mentioned).
A memcached client lib implementing both the binary protocol and text protocol, plus sharding to multiple servers. This is simpler in scope. https://github.com/williamw520/rustymem
A gzip implementation and deflate implementation. This is more complicate in scope. https://github.com/williamw520/rustyzip
Oh, nice, I hadn't seen this before. That looks really elegant and idiomatic :)
But even if you are familiar with the patterns we used and can guess the architecture, there will be a lot of unexplained code. I don't think you'll be able to extract a lot of knowledge of it.
Anyway, you should look for io_thread.rs (I think it's the most interesting file). Look how the scope are defined (especially the use and abuse of "{}"), the alternation of &self and &mut self and random methods put out of the implementation cause rustc would accept anything when they where inside.
You can also look at the mixed use of String and str which introduce a lot of chaos. And, last but not least, bonus points if you succeed to understand the why and the how of the explicits lifetimes we had to put.