Fowler's Modern English Usage 3rd Ed (2004) doesn't recognise "mouse" as an acronym but as a term within a new layer of words with new meanings, called "computerese". Fowler's adopts a wait and see approach.

The Economist Style Guide says, with regard to plurals in general, "No rules here. The spelling ... may be decided by either practice or derivation."

The Oxford Dictionary of English 3rd Ed (2010) entry for mouse reads as follows: "2 (pl. mice or mouses) a small handheld device which is moved across a mat or flat surface to move the cursor on a computer screen". The world's most trusted dictionary of English accepts both mice and mouses as correct.