What is the status/eta of this pull request? Unless integration is eminent we'd be willing to offer a bounty to help accelerate it's release. We really need this feature, our current workaround involving multiple bitcoind instances, and relaunch rescan per user session is catastrophically cumbersome.
It will get pulled/released faster if you help test it. Pull the patch, compile a custom bitcoind, then run it and report any bugs. If you don't find any bugs, add a short note either here or in the PULL request.
Testing is currently the bottleneck for getting new features...
I have been running bitcoind, in the recent past master/HEAD with patches mentioned by sipa on bitcoin's github and more recently sipa's own showwallet branch. Other than the one bug it had with the construction of the privkey for printing on dump (a typo, already fixed) and the fact that the import of each key takes multiple minutes (it scans all blocks for transactions, so that's expected, I would like to see a batch import in the future so a single sweep could verify multiple addresses) I can tell you it is working very well.
I'm using it quite heavily these days to organize offline wallets with a set amount kept on each address and then keeping the addresses and priv keys on paper in a safe.
My workflow only touches dumpprivkey and importprivkey. There is a glitch with the address balance listing after importing but it's a known bug and doesn't affect the global wallet balance consistency.
I would LOVE to see this pulled into bitcoin proper, and if you need any specific unittest written (there's a framework now, right?) I can try to find an hour to give it a shot soon.