I'll bite. The 'sort' utility wants to sort line-based output. The output of aptitude is not line-based. It uses the Debian RFC822-like format. The right thing to do would be to find a tool that sorts this output based on a particular field. You could argue that there's a hole here that could be filled by some kind of sort-dctrl tool.
I wrote that paragraph before I noticed that I already have a sort-dctrl program on my system; it's part of dctrl-tools. Unfortunately it doesn't actually work with aptitude's output; aptitude doesn't output deb822 data... it doesn't use a . to represent blank lines in its fields. :)
Anyway, I actually agree that PowerShell is pretty cool. I find it utterly unusable, however, because it's still welded to the utterly dreadful excuse for a terminal emulator that is conhost.exe. In 2011, essential features such as multiple tabs, run-based selection and the ability to click URLs are entirely absent, and the features that do exist, such as resizing windows, block based selection and changing the font/colours are buried behind a UI that seems to be actively designed to get in my way, making me want to nuke the computer and install Debian rather than be forced to use them for even one minute longer.