Too hard to predict, we don't even know any details about Sony/MS's next consoles, and we haven't seen how WiiU's launch will be.
But I'll try:
Nintendo: WiiU will do considerably worse than Wii, but considerably better than N64. 3DS will be considerably below DS but clearly dominating the handheld space. I can't say much more.
MS: Will dominate NA sales, but its situation won't improve in Europe and Japan. It'll have solid sales at least.
Sony: PS4 will have released by the end of 2014 despite their financial situation. It'll have a a better launch than PS3. It'll retain Europe and have solid sales also, but in NA Xbox hype will hurt it. Vita will have a sustainable but low console base.
If PS4 and X720 release at around the same time for around the same price, I see PS4 somewhat outselling X360, but it's hard to tell if those circumstances will be met.
No troll is too much for me to handle. I rehabilitate trolls, I train people. I am the Troll Whisperer.
