LG Optimus Slider aka Gelato shows up in Sprint database with September 11 release date
Judging by its name, the LG Optimus Slider is extremely likely to come with a slide-out keyboard of some kind. Another hint in favor of the assumption is that the smartphone is probably meant to replace the LG Remarq – one of Sprint's feature phones that launched about a year ago bearing a vertical slide-out QWERTY keyboard. Unfortunately, there seem to be no clues regarding the Optimus Slider's hardware specs at this time so we will just have to wait and see.
source: CrackBerry via Android Central