A tedious task I'm often repeating while working with Visual Studio is generating a new solution after new files have been added or some configuration has changed.
This usually forces me to close the solution, run some batch file which calls Premake, and open the last solution again.

This can be nicely automated with a VBA macro: Open the Macro Explorer (Tools/Macros/Macro Explorer), create a new Module, and add the following subroutine:

    Sub RunPremake()
        If Not DTE.Solution Is Nothing And Not String.IsNullOrEmpty(DTE.Solution.FullName) Then
            Dim solutionPath, solutionDir, premakeTarget, premakeFlags, premakeExePath, premakeScriptDir As String
            solutionPath = DTE.Solution.FullName
            solutionDir = solutionPath.Substring(0, solutionPath.LastIndexOf("\"))
            premakeTarget = solutionDir.Substring(solutionDir.LastIndexOf("\") + 1)
 
            ' You might need to adjust these
            premakeFlags = ""
            premakeExePath = "C:\tools\premake\release\premake4.exe"
            premakeScriptDir = solutionDir + "\.."
 
            DTE.ExecuteCommand("File.CloseSolution")
 
            ChDir(premakeScriptDir)
            Dim command As String
            command =  premakeExePath + " " + premakeFlags + " " + premakeTarget
            Shell(command, AppWinStyle.NormalFocus, True)
 
            DTE.Solution.Open(solutionPath)
        Else
            MsgBox("No solution!")
        End If
    End Sub

This code makes some assumptions about where the generated solution is stored, mine is in a directory named after the Premake target, e.g. vs2008, which is located in the directory where the premake4.lua script is stored.

To have the macro easily accessible, I added it to the Build toolbar: open Tools/Customize..., select the Commands tab and the Macros item. Find the RunPremake macro and drag it to a toolbar of your choice, then select "Default style" from the button's context menu to only display an icon instead of the macro name, and choose a nice icon (I recommend the coffee cup!).

Have fun!
Johannes