CryEngine 3 is CryEngine 2 with console support and maybe a few tweaks, idTech 5 is id's equivalent of UE3/CryEngine 2. UE3 has been updated to 3.5. They are not next gen engines.
UE4, CryEngine 4 and idTech 6 will be the next gen engines, and won't really be around for a while.
Maybe it's partly due to consoles, but I think it's also just because that's the way things go. The cycle between engines fits with the cycle between consoles.
Unreal Engine went 1998 (May) / 2002 (June) / 2006 (November) and so the next "sensible" time would be 2010 at the earliest, but 2011 wouldn't be too much of a shock and 2012 not unreasonable if there's a slightly extended development time.
Cry 1 2004 (March) / Cry 2 2007 (November) / Cry 4 2012(?). Even with an equal dev cycle 2011 would be a best estimate for the next generation, so again 2012 isn't particularly crazy or console focused, it's just the way it's gone, and if they are going to coincide with next gen consoles, why not optimise for them?
Playstation consoles for example went 1995 / 2000 / 2006. You can see it's not so much consoles dictating generational improvements as it is just the way things have gone. The next consoles might hit around 2012 and the next engines will probably hit around then as well, and be targetted at those consoles, but that's just because the dev cycles fell into step.