I just pulled down the 3.0.3 branch from SVN and have encountered an initial problem with the VisualStudio solution file Lucene.Net.Core.sln in the VS2010 folder.
This solution will not load in VS2010, Visual Studio complains that it was created with a newer version. Opening the solution file in notepad reveals that it was created with VS2012 (a not yet released product) It would be very helpful if those maintaining the source distribution limit themselves to released development tools only. It also make me wonder of the viability of any binary distributions; they certainly should not have been created with VS2012RC - Neal G.