Does Sony provide a sufficient range of lenses? 100mm micro? 200mm micro? 600mm? Wide zoom? 70-200 VR equivalent? Macro flash? The system is rather limited. And the Zeiss lenses look somewhat variable. The 18mm gets excellent reviews, and the 21mm might be a gem, but images on dpreview taken with the 24-70 F2.8 zoom are not overwhelming.
Why do you say the Zeiss lenses look variable? As to your other queries:
100mm micro - yes, available new and several versions available 2nd hand.
200mm micro -
yes, f4, 1:1 macro, 2nd hand only. 600mm -
yes, f4, 2 versions, 2nd hand onlyWide zoom - on full frame several, from the el-cheapo KM 17-35 f2.8-4 through to the Carl Zeiss 16-35 f2.8. Several more on APS-C.
70-200 VR equivalent - yes, available new in f2.8 form.
Macro flash - yes - twin macro flash, ring light and ring flash all available.
That's all without going into 3rd party options of course.
Also maybe of interest -
1-3x macro zoom - I don't think Nikon has one of those?
135 STF lens - not a soft focus lens - you'll find all the info you need at that link and it maybe of interest.
Autofocus 500mm f8 Mirror lens - all the normal drawbacks associated with mirror lenses, but also suprisingly high quality and incredibly compact for what you get. Not of interest to all, but certainly to some.
All provided FYI. Personally I'm a user because I like image stabilisation in the wider focal lengths.