I just learned about a Connect item entered on Friday: https://connect.microsoft.com/SQLServer/feedback/ViewFeedback.aspx?FeedbackID=475337. Here's the description in the item.
Please invoke the full powershell not a "mini-shell". Powershell is very powerful
but the mini-shell you get when invoking Powershell from the Management Studio is
missing a lot of functionality.
I'm not sure how the submitter determined that there was any missing functionality, because there isn't. SQLPS.exe is PowerShell 1.0 with the SQL Server Snapins included. All of the existing PowerShell functionality is still there. You can add the SQL Snapins by running the script Michiel Wories provided in his blog post here. (And I cited that in the whitepaper I wrote.)
Calling SQLPS.exe a mini-shell is a convenience, not a representation of its capabilities, so please take advantage of everything that PowerShell and SQL Server can do together.