I'm thinking I might just not worry about loadbalancing. Not sure a lot of people are really using it anyway... I'll see what I can do about getting some DPS-800 boards out in the next few weeks to a month.
Keep in mind - this is just my opinion, (and I'm probably biased because I have a bunch of the Dell 2950 supplies):
If I search on Ebay for DPS-800 power supply I come up with about 113 hits. If I search on Ebay for Dell 2950 power supply - I get about 300 hits.
So the amount of Dell 2950 supplies out there available seems to roughly be double the amount of the DPS-800 supplies.
Now I've already bought a bunch of your existing boards for the Dell supplies - and my original plan was to use the supplies in "clusters" - so that I'd have multiple supplies powering multiple S1 Antminers. I was going to do like 4 or 5 supplies - to power 3 Antminers. I figured that would allow me redundancy - AND still be able to keep the fans turning very low on the PSU's to keep the noise down.
So from my perspective at least - a more "full featured" product - where the load balancing is built in - and where the fan speed control works properly across all the different rev numbers of the Dell 2950 supplies - is more important than coming out with a board to support another different power supply.
So the predicament you're in now is the classic one that pretty much everybody who builds a product comes into: make the existing product better and add features - or - make another product to serve a different market.
Everybody only has so much time and energy - you've just got to decide where to spend yours.
The other thing to bear in mind is: what's your market? Right now you're selling these to people who are powering Bitcoin miners. The days of the independently powered Bitcoin miner seem to be numbered , seeing as how a lot of the high hash rate units that are coming out are now coming with their own supplies. Combine that with the recent IRS ruling - and the dump in the Bitcoin price today, and I'd even start to wonder about Bitcoin mining itself.
There's probably other markets for these boards: test labs, battery chargers? - I don't know. So you might want to think about what would sell better, a more fully featured Dell 2950 board - or a board for a different supply.
Just my .0002 BTC.