A few points...
If I could ask, was the problem with the license or the conversions? I can certainly understand if there were legal issues that couldn't get resolved, but if it was a conversion problem, I find it a little bit harder to understand. Some clarification would be most appreciated!
--Steve
I am not answering for either Bill or Clark here, but I want to point out that things were a little more complicated than they appear. Publishing a book, particularly a printed book that has to go into distribution, is not trivial.
First, the announcement of 4e caused Necro and Kenzer (who was their partner on these books) to pull these three finished books (the books just released as .pdfs) from the printer.
Artwork, etc. is generally paid for when the book is printed/released and the art contracts for these books were based on a print release and the much larger predicted sales that would have been expected with a print release.
In order to allow Bill to release these books as .pdfs he had to negotiate with Kenzer (their partner on these books) to have them released to him (kudos to Dave Kenzer, one of the coolest guys in the business). Then he had to renegotiate with the artists and author(s) because the expected profits/margins for a .pdf release are much lower than the planned for print release(s).
Second, books like this that were held back pending the GSL, and then the "revised" GSL were not converted right away. There was no sense trying to convert rules to the new system until Necro knew for certain they would/could use the GSL. By the time the revised GSL came out, apparent sales of 3rd party 4e books, and distribution of those books, was low enough that Necro and Paizo (their potential partner for new 4e books) decided against converting books at that time.
Finally, conversion of an already designed, and mapped, product to 4e might be fairly simple for a DM, but for a published product it isn't as trivial. Many 4e powers for both PCs and monsters involved pushing, pulling, etc. opponents on the battlefield. This means that room sizes and terrain play a larger role in the game.
Running out of time here, I'll just say that I think it is great that Bill went through all of the time and effort to get these books released. Obviously they are out much later than he (and many others) would have liked, but they are out. I know that Bill wants to release some of the other books that were prepped and ready to go when the 4e announcement was made, but that is going to be dependent on how these books sell.
Back to real life,
Patrick