Please do! I would think this would be very popular. It could greatly lower the risk with lithium ion batteries, especially the cheap *fire batteries, would get rid of the mAh guessing game, and provide advanced features with less weight, bulk and hassle than hobby chargers. I could see it being in the shopping cart or wish list of every member here, CFP, LPF and the foreign language forums too. Where his nimh is kind of neat, a lithium ion version would be something most lithium ion battery users should have.
Maybe ask for two more things too.
Make it 26650 sized. And that doesn't count the kind that's really 18650 size, but the contacts barely make contact with 26650's. If he can't do that, then add a connector (JST?) along with the 18650 size slots. The connector means we can build our own magnetic wires or battery holder to charge any size battery with his charger.
Adjustable current like his current charger. Something like 300mA for 16340's and 1.5A for 26650's, but I'm not set on these numbers, just wanting a good safe spread for different types of batteries.
EDIT: A high charging current isn't critical, but it'll help sell more.