While the Pending Changes window is merged within the Team Explorer, the Solution Explorer allows filtering by what is pending to be checked in. In addition Open Files filter could also be applied. When the Pending Changes filter is applied, all or some of the files could be selected and right clicked and then there is an option to do the check in. That command takes directly to the Team Explorer in Pending Changes view. See below...
For me, the best solution is based on iSid's answer: to add an external tool that pops up the old dialog.
You can do this from Visual Studio: TOOLS -> External Tools… -> Add, with the following values:
Title: Checkin (or any name that should be displayed in the menu) Command: C:\Program Files (x86)\Microsoft Visual Studio 11.0\Common7\IDE\TF.exe (this is the default VS install location on Windows x64) Arguments: checkin Initial directory: $(SolutionDir)
Here is a screenshot:
You can invoke from TOOLS -> Checkin (or even assign a keyboard shortcut to Tools.ExternalCommand* as described here) and enjoy the old goodies with a new style:
Note that this won't work if a solution is not opened, because of the $(SolutionDir) variable. To workaround this, you can hard-code the path to your workspace instead.
Additionally, tf.exe can be invoked with 'shelve' argument, which will show the old-style shelving dialog.
I think the easiest solution is just docking the Team Explorer tab as tabbed document (using the right-click menu). That way it will be equivalent to the popup dialog.
Another method is to use the Productivity Power Tools. This extension adds Windows shell integration so you can perform most of your TFS commands directly from within Windows without even having Visual Studio open. The Power Tools uses the old style windows when used from within Windows shell.