Apple’s sales decline is an 8.3% reduction compared to the year-ago quarter. Given that the most recent Macintosh news — the discontinuation of the Thunderbolt Display notwithstanding — was a spec bump of the MacBook, this is completely unsurprising. MacRumors’ own buyers’ guide shows a “Don’t Buy” indicator below every Mac except the MacBook.
I think the reduction in Mac sales can be primarily attributed to the recent lack of updates. Once Apple starts refreshing the lineup, sales will bounce back.