That version contains a lot of bug-fixes compared to SeaMonkey 2.33 (no warranty for completeness) , intensive testing is appreciated.
Be careful with Language Packs (and may be other add-ons) for 2.33, they might cause big problems with 2.35, and currently I do not know whether fix for Bug 1084258 – Language pack compatibility should be bound to Gecko branch, else undefined entity errors possible already will avoid such problems.
Backup your profile before you install and test!
Linux Users: please consider Bug 1057581 – old profile crashes on startup [@ nsRDFPropertyTestNode::FilterInstantiations]
On the same download page you will find an Aurora 2.38a1 build.