If I could just weigh in here, I'm with
@brienj on this one.
IOSU is not necessary to create awesome homebrew.
With our current kernel access, we inject homebrew into Mii Maker's userland. With this, we have access to almost everything that a nomal app has access to, so, to quote
@smealum, "we can make some kick-ass homebrew." We get access to graphics, sound, input detection and the SD Card, which very few apps actually have the privilege to.
The only benefit that IOSU will give us (emulation-wise) is USB loading and file system access. We could also launch it from the Wii U Menu, but that's besides the point. IOSU's cryptography services, GamePad tools, network tools, OpenSSL and debugging are either completely pointless or can still be implemented with kernel and/or userland permissions.