Why Is My U Visa Case Taking SO Long?
When USCIS finally reviews your application, they may choose to grant deferred action in your case. Immigration attorneys frequently call this a "pre-approval." Deferred action gives you work authorization and defers any action against you (so less worry about being removed) as long as you do not pick up any additional crimes or immigration violations.
Because only 10,000 U Visas can be issued each year, all those who receive "pre-approvals" get placed on a waitlist until a U Visa is available to them.
So, if you are awaiting a decision on your U Visa application, be prepared to wait for a preliminary decision, then be prepared to wait again for a U Visa to be available!