Ars technica is claiming that, according to their super secret source, Microsoft will only be cutting the 20GB Xbox 360's price to $299 because it'll be discontinued and replaced with the newer 60GB HDD model. They also claim that the new 60GB 360 will roll out to retailers sometime in July, refuting the August release claims that were previously rumored. Finally, Hollywood Reporter is jumping into the Xbox 360 rumor pit, with claims that their sources tell them that the Xbox 360 Pro price cut will in fact happen prior to E3, but no information regarding the Elite or Arcade is available.
This is how we see this playing out: The first week of July, Microsoft will announce that the Xbox 360 Pro and only the Pro will see a price cut to $299. Then, the second week of July during their E3 press conference, MS will announce a new 60GB HDD Xbox 360 console priced at $349 to replace the old 20GB model. Simple.
Source - ars technica
Source - Hollywood Reporter