For now it means little. As tablet/mini/note/smartphone gaming is not directly compariable to console gaming.
However, studies show 65% of tablet use is games, and 33% of smartphones.
http://www.gamesindustry.biz/articles/2012-10-29-tablets-used-mostly-for-gaming
Tablets are PRIMARILY gaming machines and their games are becoming ever more advanced.
Currently it's mostly appealing to casuals, so this is Nintendo's bread and butter and Nintendo is fighting back with WiiU. Personally, I don't feel that approach is going to go over too well but hopefully I'm wrong.
For MS/Sony they have Halo 4, CoD:BO2, AC3 (yes WiiU too) and such which will retain their base despite whatever is playing on iOS/Android.
However as ever more powerful tablets and devices like Ouya, Wikipad and others come onto the market, this will begin to change and Apple/Android will be the primary competition MS/Sony & Nintendo's next gen consoles must all overcome if they hope to remain relevant.