With Apple all but certain to announce a the 4th generation iPhone (iPhone HD/iPhone 4G) with iPhone OS 4 at WWDC the week of June 7, and AT&T to release it later the same month, why would AT&T want to release the new BlackBerry 9800 slider running OS 6.0 at around the same time?

Since 2007 the iPhone has been AT&T's summer blockbuster. It's been the phone that got the users and made the numbers, quarter after quarter. Some would go so far as to say iPhone exclusivity is the only thing that's kept AT&T competitive with their arch-rival, Verizon.

Rewind. Back in March our sibling site CrackBerry.com did a Q&A roundup about the BlackBerry Slider, which could end up being part of the Bold lineup. A full, capacitive touchscreen device with a Palm Pre-style vertical slider it would give the BlackBerry faithful the Storm-like experience needed to compete in today's mainstream smartphone market, but keep the industry-leading physical keyboard those same faithful are so loathe to do without. And CrackBerry thought it was going to be released on AT&T, and in the summer.

Today Boy Genius added fuel to that fire, saying the BlackBerry Bold 9800 slider would launch on AT&T in June, be exclusive for 3-6 months, and that AT&T had placed an incredibly large order for the device -- easily exceeding 1,000,000 units.

Repeat. Why would AT&T want a huge order of an exclusive, powerfully branded, touchscreen smartphone with keyboard differentiation at the same time they've traditionally, and successfully launched their heretofore exclusive new iPhones?

Since I've sworn off Verizon iPhone rumors this week, including rumors of Verizon iPhone ads, manufacturers and equally large manufacturing runs, and increasing chatter, I'll let you answer that in comments.