Eastern European governments like frustrating my plans. I've been wanting to do a Belarus-Ukraine-Moldova route, but the visa requirements are a pain. I need one for each of them, which you apply for at an embassy or consulate. Which, for Belarus and Moldova, Australia does not have. So I'd have to plant myself in London or Berlin for enough days to get at least two visas done, without being able to go anywhere due to lack of passport. Which pretty much rules out August/September 2013, meaning it'd have to be March/April 2014. They also require bookings/invitations, which are hard to get a long way out (because you have to plan too far ahead).
The tricky part is how you actually get between Belarus, Ukraine and then Moldova. If you go from Ukraine to Moldova, you have to go through Transnistria. Which I really wouldn't mind at all, but seeing as the Moldovan government doesn't have control over that border, when you try to leave Moldova, they'll think you've entered illegally. If I try it in reverse, entering Belarus becomes trickier.
Annoyingly, lots of people (e.g. UK citizens) don't actually need Ukrainian or Moldovan visas, which means less information exists on how to get them, or what's involved.
I may have to settle for Kosovo-Macedonia-Albania-Montenegro-Croatia-BiH in August/September 2013 instead.