Joystiq states the 40GB PS3 "will be replaced with [a] new model in early August." What this new model will entail is unclear: it could be a new 40GB bundle, or it could be something different altogether. Perhaps we'll find out more at E3?
This isn't the first time hints of a new system were revealed through retail channels. The 40GB model is currently the cheapest model of the PS3, retailing for $399. It is the only model of the PS3 that does not feature any backwards compatibility support for PS2 titles.