While I like the look of him, let's not get carried away here. He's scored against Queens Park, Dunfermline, St Johnstone and Morton. St Johnstone are the only decent side in there and they have Peter Enckelman in goals. The real test is coming up as other SPL sides become more aware of his threat.
As for him making up for the departure of Murphy, we need to replace Murphy if he leaves in the summer for the reason I stated above. If other sides move to nullify Ojamma's threat then we need to have other players in the side to take advantage of the extra space this should create.
As I said, I like the look of him as a player but let's not build him up too much just yet...