Rusted Chain

[Zarathustra]

i'm not going to go into detail as to how i let it happen, but my chain has a bit of rust around the whole thing, is it safe to use?  it's not rusted through or anything, but the links are fairly coated with rust, just on the exterior though.  i ordered a new chain, but won't have it for around 2 weeks, so, can i ride with this one, or is it a no go till then?  i'd imagine that it's not terrible to be using it, but i just wanted to make sure.

[Rema1000]

The rust may be just on the flat plates (no problem).  There's probably not much moisture that got into the sealed o-rings around the pins.  
Scrub it with WD-40: especially the bushings that rub against the gear teeth.  If those have a rough-enough surface, it will accelerate the wear on the sprockets.  If you can get them clean enough, then even that won't happen.

But really, the sprockets are cheap compared to the chain.  It would be a waste to throw away an unstreched $70 chain in order to slow the wear on $25 in sprockets.  I'd try to clean the chain, then keep using it.  When it is worn, replace the sprockets and chain as usual.