The dynamics of the collector's market for the new Presidential $1 coins are fascinating to me. The initial release of the $1 coins has an initial frenzy that dies down to a more orderly numismatic market for unopened rolls, high-grade specimens, and error coins.
The standard errors in previous coins, like off-center striking, double-die errors, or mis-strikes, may show up as with previous US coins. However, missing edge lettering on the new $1 coins opens up new discussion on coin errors, since prior to the Presidential $1 Coin Program the St. Gaudens $20 gold piece was the last US coin to have edge lettering.
With the $1 coins being as new as they are, it's tricky to know what is an error and what isn't. About.com has a pretty complete article concerning which is which in these edge lettering anomalies. “Upside-down” lettering is not considered an error on business strike coins, by the way, but it is considered an error on proof coins.
Now, back to the question in the title of the post: Is it a good idea to crack open the uncirculated rolls to look for errors? There are quite a few smooth edge error coins for auction on eBay. The first one put up went for over $600, but now they can usually be had for well under $100 but not much less than $40. For the unopened mint rolls, though, you can get them pretty easily for just about face value plus shipping. People are still paying a premium, but they really don't have to.
So for now, it would seem like not a bad risk to just open up the rolls to look for the error coins. (If you live in Florida, you should almost definitely do this, because that's where a lot of the errors have been found so far.) The only real danger is that you can't sell them later as an unopened roll. Based on some of the comments in the previous post I made on $1 coin numismatics, the rolls might not appreciate that much if they appreciate as much as Sarcasticynic saw on his roll of Susan B. Anthony dollar coins — which was basically nothing!
I tend to think the price on these error coins will continue to go down for a while. The coins aren't all out yet. The error population could be a lot bigger than it is now. Scarcity plays a big part in an error's value, so if there ends up being a lot of these smooth-edged coins, they won't be worth what people are paying for them now. So if you have one, I'd suggest that you sell it now if you're not attached to it. If you didn't beat it up showing everyone, you might want to get it graded and slabbed. A slabbed MS64 smooth edge $1 coin (mint state 64, a reasonably high uncirculated grade) is going for $149 now.
It will be interesting to see how this all plays out in three months or so.
In the early '80s I bought $1000 worth of SBA dollars from my bank at face value to look for gems. Kept about 50 bucks worth of good keepers, including some '79 "wide dates." Then sold the $950 remainder back to the same bank. Total cost: $50. If there are special coins to be found in circulation, nothing like getting them premium-free.