I’m not a huge fan of manual focus lenses, my eyes being less accurate than a good autofocus system. However, the expanding product line of Zeiss ZF lenses (Nikon “F” mount) deserves some attention from those with a compatible working style. Canon users might find the ZF line interesting too, because they can be used with an adapter on an EOS body (5D, 1D/1Ds line, etc) from places like cameraquest.com.
Of particular interest are the newly-announced Distagon T* 25mm f/2.8 and the Distagon T* 35mm f/2. Why you ask? Because my recent experience in Norway using the Nikon 85mm f/2.8 PC-Micro-Nikkor lens produced some gorgeous results in infrared on my Canon EOS 5D-IR, even at the full 12.4mm of shift. The only complaint with the Nikon 85mm is that its focusing is too sensitive, with seemingly minor focus adjustments being critical for top performance, yet requiring careful attention to achieve.
Perhaps these Zeiss offerings will offer similar performance in infrared, albeit with no shift capability but with smooth and fine focus adjustment. There do appear to be other excellent choices within the Nikon lens line, but I don't yet have enough experience with them to be confident of their performance. And except for a few rare and synergistic combinations (varying with camera model), manual focus is mandatory for achieving top infrared performance.