does anyone know if a new Mac Pro needs to come out soon?

A newer model was released earlier this year. So I don't think we'll see another model "soon."

USB 3.0 can be had using a slot card. HDMI is a function of your GPU. Most new GPUs have HDMI ports. Thunderbolt is missing, but at least now it's of little consequence. If you don't wish to buy a new Mac Pro because these things are missing, then don't buy one.

Earlier this year since my existing Mac Pro 1,1 did not support Mountain Lion, I investigated getting a new one. I decided to wait until Mac Pro has Thunderbolt. (It doesn't yet.) But then my old Mac Pro gave up on me, so I got a new one anyway. Much,much faster than my old one; improved internal layout; my existing internal HDs slide right in...

One frequent complaint about Macs seems to be: "My existing Mac still works, so how can I justify buying a new one?"

The only publicly-available information is a statement sent to Apple-Friendly reporter David Pogue by Tim Cook that the Mac Pro would get a great update in 2013.

If anyone has more hard information than that, they are under non-disclosure agreement.

There was no new model, it was just a change in default processor from 2.8 to 3.2GHz, that was all, and it is otherwise totally the same, still runs 10.6.8 if needed too.

The need for TB is miniscule on a workstation. There are some attempts to get storage arrays but then you already can add SAS/SATA, and you can install higher end graphic video like GTX 670 if needed. More video processing than any TB - which is a nice product, just more aimed it seems toward notebook users and such.

And there are the constant where is TB threads.

Intel is even reconsidering their Xeon roadmap due to when they can have new models, DDR4 around the corner.

If there is a desire that is needed it is probably SATA 3.1 if anything.

I am wating for Blu-Ray drives.

You can buy Blu Ray drives to install in a MP just about anywhere.

The late Steve Jobs descibed the world of Blu-Ray licensing as " a world of hurt"

Don't wait for Apple to license Blu-Ray.