True, but at least it's there - and these days I'd probably run speakers via USB (and I guess others will use wireless). Apple are hyping the internal speaker quality and, given their track record with previous iMacs and the iPac, I'm confident that the internal speakers will make the typical cheap'n'cheerful multimedia speakers redundant...The headphone jack on the side makes sense for headphones, but will be annoying for speakers.
If you want something a bit more "audiophile" - or are doing audio creation - #1 on the shopping list will probably be an external audio interface anyway which may have a better DAC. Plus there are plenty of nice monitor speakers which plug into USB.