I think to an extent it is. Vita is overpriced though and WiiU is just a tragic misstep (IMO). Vita aside, WiiU's numbers are fine so far. I'm very pessimistic about it, but so far sales are at decent numbers for an expensive launch console with few must-have games. It's too early to write it off (based on sales) although Europe is troubling.
However, I think tablets/smartphones are stealing a large share of the market, I think these half-dozen or more Android gaming devices (Ouya/Edge) will take a chunk, SteamBox, etc.
Simply put, I think the need for a dedicated gaming system is coming to an end. Games have become so mainstream you'll be able to play them off everything electronic - including directly off the TV sans console. Game consoles will become a niche device for an audience that expects too much from developers and won't be able to support the costs of the very games they demand. Everyone else will be happy with the games on offer, pretty much everywhere else.
This is just the beginning, of the end.