As a sax player who's also involved in midi hardware and software development, the idea that a keyboard will never be able to emulate a sax sound is pretty much the same thing we were saying about guitars not so long ago. The problem is that when designing keyboard hardware, manufacturers only have so much memory to play with so they tend to concentrate the most effort on those sounds which will give the most "mileage". Hence the recent focus by many manufacturers on muli-level guitar samples with all the associated scratches, strums and scrapes which can be used in about 70% of the onboard styles to great effect.

As memory becomes less of an issue (and less of an expense), we will begin to see this multi-level sampling technique applied to other instruments such as sax. If you use GigaSampler or EXS24 you can already buy these types of sounds from the VSL Horizon series. Here's a link to their latest saxophone volume with some demos.
Vienna Horizon Series Saxes

I really don't think you can listen to these demos and tell me that it sounds like a keyboard and a midi sequencer. Sure these are very large sample libraries but I don't think it will be too long before sounds of this quality begin to appear in keyboard hardware.

[This message has been edited by Chris A (edited 02-01-2004).]