Tokina announced AT-X PRO DX 35mm F2.8 macro prime lens. It looks different than Pentax 35mm F2.8 Macro Limited, but the specs and announcement date (jast a week after Pentax) says that this lens is one more child of Pentax and Tokina cooperation in lens development. Tokina's version of 50-135mm is also looks different but the both shares the same optical design.
http://dc.watch.impress.co.jp/cda/lens/2007/03/19/5861.html
Pentax DA 35mm Limited will feature better coating (SMC) and will be more compact. Now I have understood why John Carlson called DA 35mm F2.8 Limited the "pancake".