It’s getting hard to quantify success of Apple’s iPhone. The iPhone 3GS was the quietest launch of the product line so far, yet they managed to go through a million phones in the first weekend alone, and without too many hangups.

There were some, though, and affected users are likely less than happy. Several new customers saw delayed activation, which may still take some time. Apple hopes to assuage their pain with $30 iTunes gift cards.

Apple’s sales statement included words from Steve Jobs, who’s made headlines recently for his struggle with pancreatic cancer and a recent liver transplant. “Customers are voting, and the iPhone is winning,” Jobs said. “With over 50,000 applications available from Apple’s revolutionary App store, iPhone momentum is stronger than ever.”

Jobs couldn’t be more right, though that could mean trouble for AT&T. Complaints about poor service due to network overload come in the thousands for the iPhone’s sole US carrier. The FCC also recently launched investigations into exclusivity contracts in the wireless market. There’s been no word from the Senate committee.

This is the month of phone hype, beyond a doubt. We’ve seen the Pre release, Nokia’s super-expensive N97 spot with LL Cool J, iPhone OS 3.0, and now the iPhone 3GS. Of the phone launches, the biggest is certainly the update iPhone, though it may have come more quietly than the world expected.

Lines outside Apple’s flagship store in NY reached several hundred, but amidst some rain, they were all shuffled under Apple’s roof making this the smallest iPhone launch yet. Still, AT&T reports hundreds of thousands of preorders for launch day, which dwarfs Palm’s Pre 50,000 first weekend statistic.

It wasn’t just scale that kept the launch quiet, though. In part, it was a lack of hangups that have plagued Apple’s past launches. Apple announced both iPhone OS 3.0 and the iPhone 3GS at WWDC this year, but the set the launch days two days apart. The staggered launch was presumably to reduce server load so that new owners weren’t trying to activate their 3GS while 20 million others were waiting for OS 3.0 downloads. It was a smart move, and it kept problems with the 3.0 release and problems with the 3GS launch (so far, at least) to a minimum.

Now the focus shifts to AT&T and how their network will handle more users hoping to see the wireless carrier make good on promises of MMS and tethering. Will MMS from iPhone users bring the sole US carrier to its knees later this summer?