Go pick up a copy of WiX. It comes with a .NET wrapper for MSI that makes this easier e.g.:
PS> Add-Type -Path 'C:\Program Files (x86)\WiX Toolset v3.6\bin\Microsoft.Deployment.WindowsInstaller.dll'
PS> $db = new-object Microsoft.Deployment.WindowsInstaller.Database "$pwd\TypeScriptSetup.0.8.1.msi"
PS> $db.SummaryInfo
Title : Installation Database
Subject : TypeScript for Microsoft® Visual Studio® 2012
Author : Microsoft Corporation
Keywords : Installer
Comments : This installer database contains the logic and data required to install TypeScript for Microsoft®
Visual Studio® 2012.
Template : Intel;1033
LastSavedBy :
RevisionNumber : {B41DBDE5-CF50-42FB-AF8A-13EA3003BCA1}
CreatingApp : Windows Installer XML (3.6.3303.0)
LastPrintTime : 1/1/0001 12:00:00 AM
CreateTime : 11/14/2012 3:38:30 PM
LastSaveTime : 11/14/2012 3:38:30 PM
CodePage : 1252
PageCount : 500
WordCount : 2
CharacterCount : 0
Security : 2
Handle : 8
IsClosed : False