First of all, with regards to the IDE for Classic, check out the sticky on the DB Classic board:
http://forum.thegamecreators.com/?m=forum_view&t=103611&b=10
As for Pro, it uses a proper Windows IDE straight out of the box.
All minor version upgrades to DBPro are free. Major upgrades - like when TGC release the new DX10 version will probably not be. They are a company trying to make a profit after all...
Having said that, not everyone will want - or even have the necessary hardware to make use of the new version for a while and I guess a lot of users will stick with the current version at first.
Quote: "Also, Is this similiar to other lanugages / kits where Im going to have to buy a 'shader pack' for 29.95 to use shaders, a '3d audio pack' to use 3d audio, etc.. or is my $70 or whatever the total is going to be it?"
Some third-party add-ons you have to pay for, but the vast majority are free - including some produced by TGC. And, the things you mention are core features and I can't think of anything that you can't do even with a vanilla version of DBP with no add-ons.
Chargeable TGC packs from what I've seen tend to be for advanced features that you wouldn't expect to be part of the core product anyway. And even then, I'm pretty sure that you could still do most of the things they do in DB, but it would just involve a lot more hard work.
Differences between DBC and DBP:
Pro is a lot faster and produces proper compiled code.
It also has a lot more commands, shader and particles support and a lot more besides.
The BASIC syntax of both however are essentially the same, so if you did go for Pro, you won't have to start again from scratch after learning to use DBC.
As both versions of DB are aimed at the 3D game writer, 2D support isn't that fast - especially with DBC. I believe that Pro now simulates 2D in 3D and is therefore faster and also allows you to use the more advanced 3D capabilities - like shaders with sprites.
I'm a DBC user more than Pro, but I'm sure that one of the DBPro experts will correct me if I've got anything wrong!
TDK_Man