At Beta 3 you can import your 1.0 character. At the start of Beta 4, anything you did in 3 will be wiped. They are looking at allowing Beta 4 progress to carry over to launch, but it is not guaranteed at this stage. Probably won't know until Beta 4. Characters created in Beta 4, however, will be carried over (even if their progress isn't). That's about all we know.