Kronos is for "hard core retiming" -- leveraging GPU and built on a newer foundation than the previously-licensed Timewarp filter bundled in After Effects.
Camera Tracker is a new After Effects plug-in for matchmoving by The Foundry. It analyzes "source sequences to extract the original camera's lens and motion parameters, allowing you to composite 2D or 3D elements correctly with reference to the camera used to film the shot. You can now match camera moves within Adobe® After Effects®' 2.5D environment, opening up new, robust options for the placement of composite elements, such as the creation of Fringe / Heroes style 'in scene' titles, the virtual extension of sets", etc...Marc R Leonard has already started a tutorial series on AEtuts: Overview Of The Foundry’s New “CameraTracker” Plug-in.
Update: The Foundry has added 10 tutorials and docs for Camera Tracker (example below), and 3 tutorials and footage for Kronos in the manual.
Update 2: The Foundry has added details on buying, renting, and evaluation at the store pages for the filters.