I'd say quite possibly yes.

With bitcoinica, if you thought bitcoins were going to go up, you could buy them (leveraged if you wanted to).  If you thought Bitcoin was a giant ponzi and you wanted to short them, you could do that too.

Without bitcoinica, if you think bitcoins are going up, you can still buy them.  But if you think they are going down, you now have no way to short.  Of course you can sell what you have, but that eliminates a whole swath of people who want to short and don't have any bitcoins.