Yep. Keep expectations in check. Keep your mind open and be ready to be surprised when you are shown the devices in action (particularly in footage of new games), but even then you must keep in mind pre-release footage is often not fully representative of the end products. Always remember the days of downgrades, bullshots or bull-clips (like Killzone 2's).I'm sure the consoles will be great, but it is good to remember that this is also a time period when devs praise the new systems in every way they can imagine just to promote their own games and studios. Sometimes even if they don't have access to the new systems yet but plan to release games for them later. It definitely works. Just look at this forum.
It's okay to be excited and optimistic while not entirely believing everything you're hearing until the product is actually in your hands.
And yes, having third party developers who simultaneously have the know-how to understand how the specifications in these systems affect them and aren't under any marketing contract to up-sell any particular system does lend credence to what they're saying. But I'd say even then you should still remain skeptical (again, skeptical doesn't mean don't be excited and optimistic) until stuff's in your hands and you're actually playing it.