I live in a rural area. It's by choice, because I like to live on a big chunk of dirt, and I need to drive about 40 miles from where I work to be able to afford to do that. Since I live where cable TV doesn't go, and I'm too far from a nearest telephone switch to even get DSL or ISDN, my Internet connectivity at home is horrible (a mix of spotty cellular modem plus a Yagi antenna pointed at the crappy free municipal wifi, plus lots of multiple-hour butt-numbing weekend download sessions at the nearest SBUX, about 8 miles from home). I know that most folks have much better connectivity than me, and that I'm in a relative minority, but still, I have first hand experience with how hard it can be to stay on top of the block chain with poor connectivity. In spite of all of that, I'm not too concerned with the scalability of Bitcoin. Right now, all clients expect to stay in sync with the whole block chain in order to do anything useful. I can think of all sorts of technical solutions for lightweight clients to do useful stuff without maintaining full-time sync with the whole block chain. I think that one or more of those solutions will naturally be deployed at some point long before Bitcoin achieves success, and I think that overcoming that hurdle is a small problem compared to simply getting enough people to accept Bitcoins for real daily expenses.

I agree that scalability is a problem that will need to be solved, but I think that it hasn't already been solved mostly because its solution isn't needed so much yet, and not because it's a particularly tough hurdle to get over. I other words, I expect the scalability problem to be solved before it's the long pole in the Bitcoin success tent.