The recently announced Tokina 50-135/2.8 DX is probably the first of its class, an APS-C lens that intends to fill the 70-200mm equivalent for cropped frame DSLRs. Interestingly, the constant F/2.8 across the range should make this a premium lens, hopefully comparable to the full frame counterparts it is trying to emulate.
Expected later this year, I find this the most interesting among Tokina’s upcoming lenses, considering the specific range it is trying to fill. A 70-200mm F/2.8 equivalent will likely be a welcome entry in the DSLR lens market. This one will probably outsell the Tokina 16-50/2.8 DX and the Tokina 10-17/3.5-4.5 DX as well as the Tokina 17-135/3.5-5.6 DX.