My experience for what it's worth
Like you, I thought going with a hybrid was the best way to start. I ended up getting a Trek FX--which is essentially a hybrid between a hybrid and a road bike. It's lighter than most hybrids, doesn't have any suspension and came with skinnier, "slick" tires. I eventually swapped out the tires it came with for even skinnier, 25c, tires. I enjoyed the bike from the start. I immediately felt pretty confident on it and liked that I could easily see where I was headed, etc.
I almost immediately, however, wanted a road bike. The hybrid was great, but I found it hard to ride for more than 30 miles at a stretch. I couldn't move my hands around so my wrists and hands often got sore. I also couldn't get more aero in the wind, which made me more easily fatigued. That and I had bike lust! I was jealous of all the roadies I saw on my rides. Put simply, they just looked cool.
I bought the hybrid on Memorial Day weekend. By early July, I ordered a road bike--a Bianchi Eros Donna--and took delivery of it several weeks later. Sadly, I haven't ridden the hybrid since, nor have I had any real desire to. It's not that it's a bad bike. I just love my Bianchi that much more.
I can't say for sure whether I made a mistake buying the hybrid. After all, it helped me discover that I love to ride. I may have been more uncomfortable from the start if I'd gone straight to a road bike. My biggest regret is that I spent too much on the Trek. I originally wanted the FX 7.3, which if I remember correctly, cost about $430. However, the LBS didn't have "my size" (which itself is another story) and I ended up with the FX 7.5 that cost over $600. That's a lot of money to spend on something that I don't ride anymore. I've thought about selling it, but I keep thinking it won't hurt to have a backup bike.
My ultimate advice is that if you think there's any chance you'll want a road bike in the next year or two, buy a less expensive hybrid. Otherwise, just go straight to a roadie. It won't take you long to get comfortable on it. Admittedly, the skinny tires don't handle rocks and potholes like a hybrid's fatter tires, but you quickly learn to deal with it. As the 2007 bikes come in, you'll probably be able to negotiate a decent deal on a 2006 model. My other advice is that if decide to buy a road bike, make sure you find an LBS that takes fit really seriously, even if you're buying an "entry" level bike. Don't buy from one that merely has you stand over the bike.
Good luck with your decision.
Kate
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher