If you've been following our Windows Phone 8 coverage today, you know that anybody who buys a Windows Phone today will not be able to upgrade to WP8 when it ships this fall. If you were an early adopter that's not such a bad deal, but if you bought a Lumia 900 oh, say, three weeks ago you might be upset -- and rightly so. And rightfully angry is Luke, who sent us an email he fired off to Nokia's Stephen Elop and AT&T's Ralph de la Vega in which he asks why he shouldn't, right now, turn around and retur