His favorables have moved upwards, though "he still rates as one of the least positively viewed presidential candidates at a similar point in the campaign":
Kornacki explains why this matters:
What this means is that Romney is close to becoming what he’s always aspired to be in this race: The generic opposition party candidate, with popularity neither significantly higher nor lower than it should be.
Harry Enten thinks Obama should be worried:
Approvals are not linked perfectly with general election results. If Romney's favorables, for whatever reason, stop improving, then Obama's approvals could probably just stay where they are – and the president's re-election prospects would still be competitive. That said, I'd be queasy if I were in the White House.