From what I understand, the previous landlord (the City fan) was a tenant, and when his year was up, he chose not to renew, and left with debts outstanding. The new guy changed it round, and hopes to make a better go of it. To be fair, there's always been a pub there, so it must pay it's way to some extent.
On the weekend, I went to the Pump House to check out the stock at Cardiff Classic Shirts, and they had a number of framed City pictures there, that had apparently come from the Rummer. Fairly cheap as well - £20 each. Might be worth a visit.