At this point in time, I'd say not.
Read back over some of the philosophical debates about multi-precision architectures here (and related comments on the increased transistor cost of FP32 ALU's and why they wanted 90nm for SM3.0) and you'll see that there is quite an opposition to them. Fundamentally, if you build the architecture with FP32 in mind all the time (just as ATI did with FP24 all the time) there is not necessarily any reason to have multi-precisions.
And on that note, VS's are currently single precision - they are always FP32. Supporting multiple precision can actually require more transitors, so given that ATI has publically stated they are going unifed shading hardware its another question whether it would be a cost or a benefit to support multi-precisions on a unifed platform.