It’s much more than just about a number…
I think “3.0” will send out a message to the world: “Look, a new Blender!”. Isn’t the GUI one of the big things that the rest of the world has been complaining about? But they will be getting a LOT more!
I think it will cause the animation industry to sit up and take note: “Wow, these guys are serious!”
As an techie myself, we tend to think “Aw, it’s just a number. What’s in a number?”.
Forgive me for using this example, but why then did Microsoft think it was a good idea many years ago (when they still did not have a huge market share) to jump their Office suite version from 2.x (?) to 6.0? Because they knew the industry was comparing all the Office-like software packages out there and thinking to themselves: “This Microsoft Office must be pretty immature compared to the other packages if they only sit on revision 2.x”.
Why, with all these huge changes we could even jump to Blender 10! Then we’re out there with all the big guns!
Or what about Blender 2009? If it gets released around September it could even be Blender 2010!
(Just stretching your imagination and inviting some discussion)