First the A1/A2 revision is mentioned here:
http://www.silentpcreview.com/article226-page4.html
and discussed here:
http://forums.silentpcreview.com/viewtopic.php?t=22278
I believe that the A1 revision had a Yate Loon fan and the A2 had an ADDA fan. There was a capacitor change as well but it might as well be totally dismissed as a marketing item as the warranty coverage makes that change academic.
Now as to the A3 or whatever it will be called,
rpsgc wrote:
What's new?

6 HDD connectors (previously 4) -
330, 380 & 430W models 
9 HDD connectors (previously 6) -
500 & 600W models 
4 SATA connectors (previously 2) -
330, 380 & 430W models 
6 SATA connectors (previously 4) -
500 & 600W models 
Longer (black) sleeved cables -
All 
RoHS compliant -
All
Apart from the fact that none of these changes relate to the A1 A2 comparison there are some errors:
As seen in my post at
http://forums.silentpcreview.com/viewto ... ht=#254062 The old S12 models were
330w S12 = 5
380w S12 = 5
430w S12 = 6
500w S12 = 6 + 2 PCIe
600w S12 = 6 + 2 PCIe
So you'd need to change that first bit to:

6 HDD connectors (previously 5) -
330 & 380W models

6 HDD connectors (no change) -
430W model

9 HDD connectors (previously 6) -
500 & 600W models
next I never bothered to list the SATA connectors but they were:
330w S12 = 2
380w S12 = 2
430w S12 = 2
500w S12 = 3
600w S12 = 4
Assuming casemods listings are correct the new list is
330w S12 = 4
380w S12 = 4
430w S12 = 4
500w S12 = 6
600w S12 = 6
But who knows, they might have just gotten lazy, maybe the 500 watt is still the odball on the SATA list.
So the next bit needs to be changed, presumably to

4 SATA connectors (previously 2) -
330, 380 & 430W models

6 SATA connectors (previously 3) -
500W model

6 SATA connectors (previously 4) -
600W model
And you missed the biggest official change of all:

1 PCIe power connector (previously 0) -
330, 380 & 430W models
as the vast majority of us retail customers didn't get a PCIe power connector with our A1 or A2 S12 power supplies.
So for a wrapup we have

6 HDD connectors (previously 5) -
330 & 380W models

6 HDD connectors (no change) -
430W model

9 HDD connectors (previously 6) -
500 & 600W models

4 SATA connectors (previously 2) -
330, 380 & 430W models

6 SATA connectors (previously 3) -
500W model

6 SATA connectors (previously 4) -
600W model

1 PCIe power connector (previously 0) -
330, 380 & 430W models

Longer (black) sleeved cables -
All

RoHS compliant -
All
feel free to correct, contradict, or add to the list if you know something...