Is Powershell a mature enough tech for enterprise to be using? Are its many benefits worth the time and effort to convert existing VBS scripts, or would you only use it for new scripting projects?
We are currently using a mixture of vbs and batch files, with a login script as opposed to alot of GPO. We don't have a huge number of .NET programmers, whereas just about everyone at least knows a bit of VB.
Yes. PowerShell brings into one environment the power of .NET, COM, WMI, and more. I use it every day to administer a family of 30-or-more servers, and it has proved to be both stable and productive.
I think PowerShell is a powerful thing. Microsoft is going into the "administer everything from powershell" direction (MS Exchange management shell, SharePoint 2010 management shell). This makes me think that this scripting technology will not die soon. Another thing - since the administration scripts are written in PowerShell, you can learn a lot from them, and hence gain more automation of your administrative tasks.
“Mature enough” is slightly subjective and depends on what you mean exactly.
1) Is it powerful enough to get the job done? -- Yes. But it is not the best tool for all the jobs; think, choose.
2) Is it bugs/issues free? -- No. To be prepared and informed you may want to take a look at some most voted bugs/issues in here: https://connect.microsoft.com/PowerShell/Feedback
3) Is it easy to learn? -- It depends; basically I think it is not easy for not professional programmers. But it is definitely possible, step by step, having fun: http://blogs.msdn.com/b/powershell/archive/2010/03/09/falling-is-learning-just-focus-on-having-fun.aspx
It’s a good idea to start using PowerShell for new tools. As for the old tools (e.g. VB), I would not convert them into PowerShell unless there are good reasons. In most cases they can be perfectly called from new PowerShell tools.