The Japanese retailer Camera Sakuraya has listed the smc PENTAX-DA★ 50-135mm f/2.8 ED [IF] SDM lens as “completed production” and “limited stock” (the lens is no longer listed at Adorama and B&H):
There have been rumors that Ricoh is working on a new HD Pentax-DA★ 50-135mm f/2.8 ED PLM AW lens:
Rumors about two new Pentax lenses: 70-300mm f/4.5-5.6 and 50-135mm f/2.8
More discontinued Pentax lenses can be found here:
The Pentax smc PENTAX-FA 50mm f/1.4 lens is listed as discontinued
The Pentax smc PENTAX-DA 18-270mm f/3.5-6.3 ED SDM lens is now discontinued
The HD Pentax DA 15mm f/4 ED AL Limited silver lens is probably discontinued
Pentax DA 40mm f/2.8 XS pancake lens listed as discontinued in Japan
Via Asobinet