Hybrids can be uberlight like jbc's all carbon hybrid, but for most people the weight of the bike isn't going to be a huge factor on speed unless you are going to be doing extreme hills all the time.
My hybrid weighs about 25lbs and that should be light enough for general use.
With that 25lbs hybrid with suspension fork and everything I can ride at speeds between 22 and 25 for miles btw as long as there aren't too many hills.
If you want to go faster, there are two main factors: your engine and your position ... those make 90% of the difference ... the other factors like the bike and the wheels and the weight and such may seem important but they are not.