well to be precise modern technology has come far from the earlier springs and there are a variety of springs made to specific needs and can be made stronger by using titanium or chromium.

Anyway it is better than the pyrotechnic bolt that seperates the external tank and boosters in the shuttle.

I'm not worried about the Ares I (yet )

If you saw the Science Channel Series "Moon Machines", you would know that ALL of the Apollo equipment (Saturn V, Commond Module, LEM, Space Suits, etc) had many, many design issues that on the surface seemed insurmountable -- but all of those problems were overcome.

I suppose it is possible that the Ares I, Ares V, the Orion CEV, or the Antares LEM would have so many problems that the whole constellation program would be put at risk, but it's too early to say that right now.

I agree. I doubt that NASA would change their plans this far into development if problems start arising. Its just a case of how many fundamental problems will arise up until the new rockets and CEV is flying. Hopefully everything will work out well and these new rockets and spacecraft will be more reliable than the current space shuttle and the external fuel tanks.