A clean swap over does not look like it would be necessary at this point. You would still need to download an updated wallet whether we did a hard fork with our current chain or a clean swap on an exchange to a new chain. Because we are working on forking, it means no coins would get lost in translation nor would we have to organise all the coins being moved on to an exchange. I'll have a very bold pronounced list ticking off every service/exchange we know has updated and we want to give ample warning/time to do an update before the fork takes place.
Worst case we have a bug or two with staking or an issue that causes our market to be frozen for a day or two while we resolve any issues. However this is why we're (well Presstab - he's working like a machine and has so far been very professional, also David from MINT has stepped in to help immensely) taking good time testnetting & working rather than rushing. Because of the time, testing, experience of the devs. and 'vetting' being done I doubt this would be the case, but you can never be 100% certain. At our market cap, a hiccup isn't going to kill us, and once it's sorted we have more room & potential to grow.
I've put the shout out to a couple of other well-known devs if they would like to 'vet' the code before final PoS kicks into play (and offering a small reward for their effort). It will of course be on github for weeks before the final transition. The exchanges will have weeks to vet the final update code themselves also before the PoS switch takes place (including guys from Cryptsy who visited us in IRC yesterday (wink)) - I've offered them a thank you reward if they would like to vet the code for us also.
Won't be rushed, won't be (huge) hype until it's all cleanly done and 100% confirmed, but we want it done as professionally as possible obviously ideally with no hiccups. Presstab has been very good, and made it clear payment for services is not necessary until everything is successful. He'd also like to stay on board afterwards in a more official manner, and at this point I'd love to have him.

Rofo and I continue to have very productive conversations on IRC. There are so many variables to consider when going PoS, that it takes very careful planning. We are still firming up the details, but everyone do realize that we are working hard to get the framework implemented into the source code so that we can hash out some testing.
If anyone has any questions for me I am typically reachable on IRC (presstab) or PM me on btctalk.