I have a late 2007 MBP running Snow Leopard 10.6.8 and I'd like to upgrade to Lion. It currently has X-code tools 3.1.2. I need to keep this version as the machine is used for testing backward-compatibility as part of software development. If I upgrade to Lion, will the X-code tools automatically update to 4? Excuse the awkward questioning, this isn't my field! I'm also hoping to get a MBA very shortly. Will I still be able to sync this with my MBP if the latter is still using Snow Leopard? I'm thinking mainly of moving emails over to the MBP and photos in Aperture. Many thanks!