I use a simpler approach: Jasper Smith's Reporting Services Scripter (http://sqldbatips.com/showarticle.asp?ID=62). Keep everything saved off onto a separate machine and you can migrate pretty quickly. Clearly not as 'available' as mirroring but I think everyone should have this layer of recoverability scripted out and ready to go.
Best,
Kevin G. Boles
SQL Server Consultant
SQL MVP 2007-2012
TheSQLGuru on googles mail service