"I just received an email from Sprint that 4G (WiMAX) is now available in Chi-town," Chicago resident and Broadband Reports reader bshelly writes in. "I also checked the Clear.com website and confirmed that Chicago is indeed live and orderable." Chicago isn't the only new market on tap this week.

After officially launching service in Philadelphia late last week, Sprint has also launched service this week in Dallas/Fort Worth and the North Carolina cities of Charlotte, Raleigh, Durham, Chapel Hill, Cary, Greensboro, Winston-Salem and High Point. Users alert us to the fact that Clearwire has also "soft-launched" in both Austin and San Antonio, though those markets won't officially go live until November 1.

As in other 4G Mobile WiMax launch markets, Sprint is offering users dual access to their EVDO and Mobile WiMax service for $70 a month, though you'll need their 3G/4G U300 USB Modem. For the time being Sprint's 4G service is uncapped, unlike their 3G service which comes with a 5GB monthly cap.

Sprint Nextel unveiled their first quarter earnings this morning, which indicate the carrier is still struggling with the massive customer defections that have plagued the carrier since their troubled acquisition of Nextel. According to Sprint, the company lost 182,000 net subscribers, thanks to additions from Boost Mobile and their partnership with Amazon for the Amazon Kindle. That said, the company still lost 1.25 million "postpaid" customers to competitors like AT&T and Verizon, suggesting that the company's customer service issues aren't yet behind them. Sprint posted a net loss of $594 million, up from $505 million a year ago, while revenue fell 12% to $8.21 billion.

While Sprint's new XOHM mobile WiMax is officially only commercially available in Baltimore, reports suggest that looming launch market networks (Chicago, Boston, Dallas, Philadelphia, Washington DC, Northern Virginia) are now live, though only in a testing capacity and not technically taking customers yet. DC and Chicago are supposed to be the next markets that come online, with the remainder scheduled to go live before the end of the year. On Wednesday, Sprint plans a marketing extravaganza in Baltimore officially heralding the new service's arrival.

Last week a tipster alerted us to the fact that Sprint would be unveiling their pricing and packages for their Xohm mobile WiMax service this Friday on the company's website, with a real Baltimore "launch" October 6. It now appears those fireworks will be two days later. According to invitations being sent out to reporters and analysts, on October 8, Sprint will present their new service at a media event at Bond Street Wharf Park in Baltimore. The event will feature presentations by company CFO Barry West, CEO Dan Hesse and Intel exec Sean Maloney.

A tipster tells us that Sprint's mobile WiMax Xohm service should be launched in the Baltimore market on October 6. Xohm sales kiosks for the new service should show up that day in the Columbia, Arundel Mills, Harbor Galleria and Marley Station malls. The tipster says that the real introductory date will be September 26 (next Friday). That will be the date of the real fireworks, so that Sprint makes their promise of a Septmeber launch.