Actually, from what I am to understand, we didn't buy the new Nova LFS busses, but rather leased them. (Although I could be mistaken on that.) As for numbers, I beleive we have recieved 25 of them, and have 18 more on order. The new shipment of busses will differ slightly, in that the windows won't have a bar across the top third of them. They are also testing a bus with fabric seats and cushions on the handrails, so we might start seeing those on the new batch, if they prove worthy.
As for replacing the old RTS busses, some will be taken out of service... others will be reconditioned and brought back into service. The RTS bus is a strong, durable, proven bus, and there's no reason to take a bus out of service if it's still running great.
The new system we have in place for the busses is called "Magic On Demand" It's designed so that busses will be dispatched by demand. So if there's a huge crowd at one of the All Star resorts for the Magic Kingdom, they'll dispatch extra busses to that location to meet the demand. This system is designed so that the busses will be utilized more efficiently. Now, of course, there are still some kinks to be worked out in the system, but we're working hard to resolve them.
I personally use Disney Transport all the time when I visit the parks, and I've never had to wait more than 5-10 minutes for a bus. Although, I'm sure during peak times, the wait might be a little more. I know there have been times when I've heard of enormous waits during park exits for certain resorts, but when you really think about it, it's to be expected. I mean, you have 30,000 people all exiting the Magic Kingdom at the same time, so my suggestion is that you either leave a little bit early, or you mingle around the shops in the park till it quiets down.
Oh, and as Fievel pointed out, yes, sometimes we will call in Mears or other charter busses to come in and help us with the exits. I remember on 9/11/01 when we had to evacuate the park, they brought in a few Mears and Dynamic busses I believe.
As for the Monorail Expansions... don't hold your breath. Like Smee said in an earlier post, it's simply more cost efficient to use busses rather than expand the Monorail. Rumor had the proposed expansion to be over one billion dollars. That's an awful lot of money for a non-revenue generating item.
In addition, in order to do so, we'd have to totally rebuild the current monorail system in order to incorporate it. Not a fun idea.
Don't get me wrong though... being a Monorail Pilot, we all would LOVE to see new trains and a system expansion. Then again, we'd also all love to have Eisner's bonus.
All in all... when you really think about it... Disney Transport is a very complex system that runs pretty darn efficiently. I was once told that we are the 7th largest transportation system in the country. I think we do pretty well.