Cadillac apparently has internally approved development of a modified Zeta platform called Omega. The Zeta platform is the GM Full-size Rear-wheel Drive platform. GM platforms lately have received greek letters for their internal references. The Zeta was originally designed as a replacement for the W, H, and K platforms, but was not used, instead becoming the underpinnings of the Chevrolet Camaro. The long wheel-base version of Zeta has also arrived in the form of the Chevrolet Caprice police vehicle.
Zeta has an independent suspension utilizing MacPherson struts coupled with a dual ball joint lower A-arm in front and a four link independent setup in back. Holden is working on a variant of Zeta to make it lighter and more economical. One would suppose the new Cadillac Omega platform would be lighter and more premium — utilize more expensive components for the same platform in order to save more weight and improve performance.
The upcoming Gen V V-8 is the suggested powertrain for the new Top-Cadillac. This seems a good selection to me as it should give terrific power and relatively good fuel economy for what promises to be a heavier vehicle.
The upcoming ATS will be on the Alpha platform, and the refresh of the CTS will also go onto a long-wheelbase Alpha. Alpha was originally designed as a small rear-wheel drive program. The advantage of the new Omega platform perhaps is that it allows for a even longer wheelbase for the upcoming Top-Cadillac. Also, with the addition of the Omega platform for the larger Top-Cadillac (ULS?) Cadillac will have a nice mix of platforms to develop from. The upcoming XTS is on the Epsilon II Front-wheel drive platform, although it may be all-wheel drive with rear-wheel drive bias. It will be interesting to see how the XTS, ATS, CTS, and SRX fare in the showroom.