Just as promised when we first met the carrier's Viper 4G, Sprint's placing the device up for pre-order today. Notably, rumors of an eventual April 22nd release date can now rest comfortably, with The Now Network saying it'll do its best to get the Gingerbread handset on all early-adopting hands before Sunday. For being one of Sprint's initial LTE slabs, the Viper bears a flexible $99 price tag -- of course, that's with