according to IDC, dropping 14% in the last quarter. IDC blames some of that on poor adoption of Windows 8, which seems like a pretty good guess to me.
Tablets, on the other hand, are still growing strongly. The 7 inch size seems to be the most popular one, whether it's the iPad Mini or one of the many Android tablets in that range. Every game maker I talk to (and I talk to a lot of them) has their eyes on tablets as the Next Big Thing.
Still, we're still in the early days on tablet games. Designers have to figure out ways to get around the lack of physical controls, and there are still many innovations to be found in designing for a touch interface, all the different sensors, and all the various means of connection.
For game marketers it just means things are changing even faster. You'd better be re-examining your marketing plans frequently as the market changes. Demographics are shifting, platforms are shifting, business models are changing, marketing channels are opening and closing... It's like trying to navigate through the breakup of an icecap. What looks like clear water ahead may turn out to be a dead end, then the ice closes in and you're trapped.
On the other hand there's a chance for new players to break through the noise and find a market. It's encouraging that new games and new publishers continue to make the Top Ten list of the highest-grossing games on iOS and Android. That means there's not complete dominance by large companies.