It's mainly a performance thing, from our perspective, although Microsoft gets some development benefits, and developers who are hosting PowerShell get some advantages, too. FOr us, there's a big execution performance benefit, because functions and scripts aren't interpreted each time they're run, but are now compiled and executed, resulting in faster execution. In some cases, the compiled result is cached, speeding up future execution, too, since the compilation "hit" is bypassed. So the first time you run a script it might be a wee bit slower than under v2, but future runs should be much faster. This applies to scripts and to functions contained within scripts (and modules); any ad-hoc stuff you type directly into the console doesn't benefit. So there's now a big performance gain in modularizing your functions into scripts.
Looks like new technology alright and a hybrid of the two. You're still going to need lots of hardware, and MS OS to run it - but seems like an improvement. They mention Python, so I'm wondering if .net can now run Python script?