It's definitely worth learning. Do you ever convert text? Do you ever manipulate XML? Do you ever automate anything? Simple example. Someone gives you a comma delimited file and you need to pull some fields out of it to import into some other tool/database or to create some list for your program.
If the csv has the field names in the first line of the file, you can do the following in Powershell:
$Data = import-csv "something.csv"
You can then refer to your data using the field names. If you had a field called SSN then you could say $Data[n].SSN. You could also just pipe the import-csv command to something that processed the data including exporting it as XML/html or anything you want with just a few commands. Powershell is full of stuff like this.
It's a tool that gives you tremendous access to a ton of stuff on your workstation and servers, including the complete .NET library. It's a tool that isn't targeted at a type of person. Maybe it's just that the Admin types have been quick to realize how useful it is. I use it every day.
To actually answer the question asked, I use it to automate things I do everyday. I am trying to make it my single scripting language, replacing the things I did in perl, python, vbscript, .bat/.cmd, and one off little utility/conversion programs that I would create.
