Sharing my personal experience here.
I bought a hybrid 3 years ago, after deciding I wanted to cycle. After recently going through the want-to-upgrade path (SD, Sn would know!

), I've only just bought myself a road bike. I was lucky and got a decent (actually, it's pretty tricked out) bike 2nd hand. It's a cyclocross, so it's quite close in spec to my previous bike.
It's very different from the hybrid, and I wouldn't have known the difference had I not taken the plunge. I'm still very new to drop bars and all, but I've commuted to/from work (It's less than 5km from home, so an easy choice for me) the past 2 days, and I'm slowly getting used to it. And you'll laugh seeing a roadie on the pavements, but yeah I laugh at myself too.
My take, instead of spending the money on upgrades, put it in a fund. Save up until you eventually hit 1-2k where you know it's going to be spent, then buy your bike. If you prefer, camp on tgp and wait. You may get lucky and stretch your dollar more. Of course, selling your current bike will nett you a bit more money, but you'll be bike-less for a while.
I won't dare cycle near wild dogs.

Don't think I can outpace a hungry pack!
/Dan