You can go to other places to find out which commands have been added and indepth analysis of all that is new with this. Here, you will only find my short take on what has been added.
Firstly, nothing dramatically new as far as I am concerned, because I am a 3D user. The only things I can think of as far as 3D is concerned, is that there has been a heavy effort on the part of the programmers to tighten up the display - ie when using 3d shading. The shading in previous versions has sometimes not looked the greatest, (it seems to vary from drawing to drawing), so this is most welcome, and is the part I look forward to most in the new release.
It seems a far more responsive program than before, but this is hard to judge as I've only tried it on an old Athlon 3500 with a cheap video card, on Windows XP. I'm curious as to how it goes on Vista.
For 2D users and new users the picture is different: A rearranged ribbon for commands, and for the first time, parametrics and constraints. Not to be left out, dynamic blocks have been revamped to make them easier to use.
Because the parametrics are only usable in 2d, I don't plan on using them. My work is so varied that dynamic blocks are not much use to me either.
Some 2D draftees will no doubt get excited by the parametrics. When I say 2d, this is not strictly true, as one enterprising person made two 3D blocks that each contained lines in them, and did a stunning animation of a rack and pinion.
There is a new file format, R2010.
Just in case you don't know what parametrics are, all it means is say you draw a rectangle and tell it that the two horizontal lines are always to be parallel (ie constrained) and the same for the two vertical ones, then if you stick one of the new special dimensions on the rectangle, then this gives you the ability to click on the constraint dimension and change it. This will cause the geometry to change. Quite a leap for Autocad, shame it is not available in 3D!
There is now the ability to bring a pdf file into your drawing. I have just tried this out and it is quite impressive for two reasons:
1. In a multipage file you are given the option of picking which one you need.
2. You can draw lines etc over the top of the pdf and it will snap to sensible parts of the pdf!
There are other items, such as measuring that have had an extreme makeover and I look forward to having these tools available. For instance there is now an area tool that highlights it's boundary so you can tell what is being measured. A small thing, to be sure, but if you add up all these small things, they start to add up to a compelling release.
Remember the fun of hatching using Autocad? There is now a new helper in your war: little red circles showing where the problem is. Again a small thing....but.
Express Tools now come ready installed on the menu bar, which by default is turned off!
If you want it back, there is a little down arrow next to the printer button.....this is the only thing you need to remember!