Except all three of those statistics are worthless.
1. 0.55% complain to AppleCare
We have no idea how many people suffer from the problem and did not call to complain. This is a problem that is getting a lot of news coverage. It seems likely that people who suffer from the problem and saw the coverage would have no reason to call, they can just wait and see if there's a fix coming.
2. 1.7% return rate
30 days are not up yet, a lot of people could be just waiting for a fix and then deciding if they want to return. The real return rate once we cross the 30 day mark will probably be a lot different.
3. <1 more per 100 dropped calls compared to 3GS
This could be really bad or really good. We have no way of knowing without knowing how many calls the 3GS drops. If the 3GS drops 0.5 calls per 100, then this is a near 200% increase, which is a huge problem. But if the 3GS drops 20 calls per 100, then this is merely a 5% increase which is not that bad (but something tells me the 3GS doesn't drop that many calls).
So, all three statistics tell us next to nothing how severe the problem is.