As you probably know from other threads I have a 44cm Ruby Pro. I bought the Ruby because last year it was really the one and only small, high quality race bike available for someone my size without going custom. I figured if I was going to upgrade going with another aluminium bike wasn't really what I would want to do and that was pretty much what all other bikes in my size were- I wanted the new one to be one that I wouldn't feel the need to upgrade again in a year. I was looking to lose some weight (about 4lbs from my old bike so not insignificant) and get a component upgrade. Also, as I race, I really wanted to stick with standard equipment, so not having to have 650c wheels was a real plus - I have no probs with fit, toe overlap or strange/sluggish/twitchy handling, no matter what other people think about 700's on a small bike.
With the success of the Ruby last year - they were very popular and it was difficult to get hold of one (plus the very small sizes were produced in rather small quantities- my 44cm Ruby Pro is one of 9...) there are more companies producing high performance bikes for us smaller folks. I'm not in the market for a new bike, so I haven't really looked, but I've heard other big names are getting into the small bike market. I've heard that even Pinarello has a 43cm women's frame this year.