Let me just say that, as a programmer having used BOTH, good riddance UWindows, and I hope you never come back!
UWindows was a HUGE pain to code for, which is why you will NOT see it come back. The new system is much easier (mostly due to advances in the language itself, plus the (albeit very half assed) GUI designer.
That said, UWindows was more fun to use, imo. What they REALLY need is a system like Visual Studio (or something like it), where you can come in and "paint" your controls on your "page", save it and viola you're done. Having done an entire menu (of over 20,000 lines of code), I can say this would save huge amounts of time, and take the annoyance out of doing the menus.
They can start by buying UDE (WOTGreal), and working from there to turn it into something that works cohesively with the engine. Not just as a GUI designer, but as a debugger and programmer TOOL instead of a crappy gay debugger (which sucks, btw), and a crappy GUI designer, and being forced to use notepad or some other 3rd party app to program in. Uscript is a huge part of the unreal engine, and needs some major attention. The level editor was given an overhaul, but it takes too long to load and hogs too much resources to be useful for a programmer. So something else, like UDE, would be wonderful.