The very existence of the version 2 box is down to the cost savings PACE were able to make using a more integrated chipset on the mainboard. This allowed a smaller design to be created around the chipset which also reduced production costs even further and you would think increase reliabilty
The same principle was applied to the SONY Playstation 1 when the design was revised and it shrunk considerably.
The basic functions of both PACE SKY+ designs are identical and I expect the upcoming Amstrad design will not differ in the basic functionality either but will probably look very different.
Amstrad are in the testing phase of their new Sky+ box .
One other difference - it is rumoured on DigitalSpy that Sky+v2 boxes have a softer picture than v1. I have only ever had a v2, so can't comment. I would be interested to hear from anyone who's used both though.
As shawkins002 says the only new manufacturer known to be producing SKY+ units is Amstrad. I would not be surprised if SKY got others involved simply because the potential market is going to be very healthy. After all there are now 250,000 SKY+ units installed and SKY must surely be looking at having it as the default STB for new customers especially as Cable can not offer anything similar and DTT can.
The lead in time for a manufacturer to get a license and contract then a basic design is so long that if someone like Panasonic were considering lauching this year news would already have broke about any deal.
Every digibox is faster than the first generation PACE 2200's