Following months of rumors, a date has reportedly been set for the launch of the iPhone 5. In other welcome news, two industry reports chart the significant growth of mobile ad spending and app revenues. Meanwhile, Android developers received word of important policy changes for the Google Play app store.

Apple will announce its iPhone 5 Wednesday, Sept. 12, with the device hitting stores Friday, Sept. 21, according to new reports. According to a Mashable piece, the launch will be made via a special announcement and will also include a new iPod Nano and possibly the iPad Mini. As CNET reports, Apple expects to produce 20 million iPhone 5 units in the September quarter alone. And J.P. Morgan predicts Apple meeting – or exceeding – the current sales estimates of 39.5 million for Q4 2012 and 37.8 million for Q1 2013.

According to a new report from eMarketer, global mobile ad spending is projected to hit $6.4 billion in 2012. Driven by strong growth in the U.S., mobile ad spending will increase about 62 percent this year, putting the U.S. market ahead of Japan for the first time. The research estimates the U.S. mobile ad industry will balloon 96.6 percent to $2.3 billion in 2012. Mashable shares a chart that depicts mobile ad spending worldwide (by region and country) from 2011-2016.  

Revenues generated by iOS and Android apps are forecast for healthy growth, says Mobile Marketer. New data from Flurry Analytics projects app revenues to grow 60 percent to $8.7 billion, with advertising as the fastest growing revenue category. According to Flurry’s data, iOS and Android apps tallied a total of $5.4 billion in 2011 from premium sales, in-app purchases and advertising sales. Interestingly, in 2010, the top 25 ranked titles on iOS and Android generated 28 percent of revenue from premium sales and in-app purchases, but this year, they are expected produce only 15 percent of revenue. “What’s most surprising is that that mid and long tails are getting fatter not skinnier,” said Peter Farago, vice president of marketing at Flurry Analytics. “More apps are making more money.”

This week, Google Play delivered a letter to its tens of thousands of Android developers, informing them that it is making numerous changes to tighten its policies. Changes included naming apps, app icons, payments, privacy, spam and advertising. “All in all, this is a pretty strong list of ways that Google can now use to better control what kind of apps appear in the store, and perhaps attempt to raise the quality in the process,” writes Ingrid Lunden in her TechCrunch piece. Developers of new apps will be required to meet the new policy changes immediately, while apps that violate the new rules will have 30 days to comply or risk app store ejection. You can read Google Play’s full letter here.