Globe: Romney's "slip" just that
The Globe's write-up of Mitt Romney's Obama/Osama error starts by endorsing Romney camp's explanation--i.e., it was an innocent mistake:
In an apparent slip of the tongue on the campaign trail yesterday, Mitt
Romney mixed up the names of Al Qaeda mastermind Osama bin Laden and
Democratic presidential candidate Barack Obama. [emph. added]
Question is, does Romney really deserve the benefit of the doubt? After all, as TMZ.com demonstrated back in July, Romney seems to get a kick out of conflating Obama and Bin Laden:

Before conservative readers rush to point out that, as the Globe mentions, Ted Kennedy made a similar mistake in '05, let me note two big differences: unlike Romney, Kennedy started with the wrong name and then got it right. Romney did the opposite. What's more, Kennedy has a history with this kind of stuff (see #90), while Mitt tends to be a pretty good speaker.