I've been pestering NI to add Lua scripting to Reaktor - now it looks like I can stop pestering and enjoy it from an external source, with the GUI and interconnection problems all taken care of already.
Yes, there's already scripting in Lemur but the app costs literally ten times the price of TouchOSC - I've worked in it a bit and it's slightly annoying that it's yet another non portable toy language (KSP anyone?). The nice thing about Lua is that it's an open standard and it's already in, for example, the Pure Data beta. I expect it to show up in more places soon too.