Specific to Autodesk (& related more to Inventor):
1) Direct modeling (a.k.a Fusion) will be tightly integrated into Inventor without destroying parametric workflows.
2) As a result of implementing Fusion into Inventor a lot of smaller spin off tools and workflows will come out of it that weren't exactly planned but will make the everyday power user's life much more efficient. I'm speaking of things that can't specifically be predicted, but will only come about organically.
3) I believe Autodesk will increasingly streamline the multi-directional functionality between their manufacturing and AEC products to a point where the models seem native to which ever system you're working on even though it would be from another CAD package. For example, if a building was created inside Revit and was "ported" over to Inventor, there would be a model browsing history that would appear as if it was originally created inside of Inventor and the Inventor user would be able to make changes to that building (probably based on rules the Revit user set up when exporting) in order to facilitate a better integration of the product that the Inventor user's company is manufacturing.
4) Expanding on the streamlined integration of products, Autodesk will begin to bring some of the functionality and toolsets of products used inside the gaming and special effects industry into it's technical 3D modeling products.
5) I believe rules based design will also be tightly integrated into Inventor (and Revit for that matter). This would be done in a manner where it would blur the line between parametric modeling rules based design.
6) AutoCAD will still be around, but it's retirement will be seen on the horizon as a more definitive date. It's just too deeply entrenched in workflows and processes around the globe to go away in the next decade.
General CAD predictions:
1) Cloud based computing will present a new paradigm in licensing CAD packages. It will be a more affordable solution to smaller scale companies and maybe even individuals who contract with larger companies. It will also mean that Automation of these CAD packages could now, more easily extend to non-traditional CAD users (i.e. sales force, customer base, shop floor, etc.) where a custom UI is developed on top of the cloud based CAD package. I think there will be many spin-off developments leveraging the expansion of this technology because the bandwidth speeds will only get faster (and more stable) over the next decade.
2) I agree with the assertion that Solidworks and Inventor will be the two dominating forces in the 3D (mech) CAD marketplace. I think that the others will still be out there but their impact won't be "felt" nearly as much.
3) I think that the uber-high-end CAD packages like Catia and Pro-e will be relegated to live out their days where they are too deeply entrenched to be replaced. I think that the ratio of the price point to what functionality is offered between these high-end packages and the "mid-range" packages will be harder to differentiate and therefore cause companies to re-evaluate their expenditures in their CAD software. I definitely believe that (at least) Inventor will meet or even beat the functionality of these high-end packages and possibly the other packages will do the same (aside from Solidworks, which is a separate subject - which takes me to the next point).
4) Let me preface this "prediction" with the statement that I am not familiar enough with either Solidworks or Catia (especially Catia) to know their finer points in order to accurately predict what will happen with them or say what they should or shouldn't do. I am speaking from a point of view of an outsider with passion for CAD and as someone who has an opinion based on general observations. With that said, I agree that Solidworks will either have to separate itself from Dassault or Dassault should somehow (and I don't know how) integrate those two packages. From what I understand, Catia has, what I call, a "use-based" pricing structure where if you don't renew the "subscription" each year you won't even be able to use the software that you currently possess. That strategy, IMHO, is a recipe to stifle growth when these "mid-range" CAD packages are making such strides each year in closing the functionality gap.
5) I think by the end of the decade we will be on the brink of some revolutionary changes in the User Experience where the traditional monitor, mouse, keyboard, and potential 3D motion controller will be replaced with a totally immersive experience that further enhances productivity and functionality. I don't think it will be in practical use by the end of the decade, but I do think that it will be close to that.
One final prediction... I think that MCADForums will be bigger and better than ever. I think that as more people move into the 3D realm, the forum user scrolls will increase in-turn. My only hope is that the current decorum is maintained. From the friendly banter, to the vigorous debates, to the willingness to help newbies and oldies alike without passing judgement or sounding condescending; I hope that this forum continues to attract the true CAD junkies out there. From any CAD package.
...Jeez, I sound like freakin' politician!