I think that's the biggest part of why I'm so curious about the SL: I'm trying to figure out who it's for. The marketing stuff says "pro" a dozen times, but I'd really like to know what segment of the professional market they're aiming at. If I simplify it I'd list the segments as: photojournalism, forensic, fine art, weddings, sports, fashion/commercial and video production.
Photojournalism: realistically, you'd want two bodies if you're a PJ who is out in the field. That's $15,000 for two SL bodies. And the only native lens is a 24-90. The 70-200 on a CaNikon DSLR body is pretty much the standard kit for PJ, maybe along with the 24-70. I just don't see someone taking a pair of SLs to Syria or other dangerous or remote locations.
Forensic: No ring flash, and I think forensics requires certain types of SD cards for security reasons.
Fine Art: I could see the SL having a place here, especially since it can make great use of M lenses and soon it'll have an S adapter, too. But it's up against some heavy competition in the form of the Pentax 645Z - a very good medium format digital. The 645Z body costs $500 less than the SL and the Pentax lenses are even cheaper, relatively. Pentax has an amazing 55mm lens that costs $1,000. And of course there's also the 5DSR and D810.
Weddings: Again, the SL is up against the Pentax and the D810/5DSR.
Sports: This is where I feel like Leica believes the SL belongs. Their marketing material certainly makes me think so. Half of it has been images of the SL's viewfidner locked on to a Ferrari F1 car racing on the track. They put it in the hands of Sebastian Vettel. It would be matched up vs. the 1DX and the D4S and it might be better. But the SL has zero lenses to compare against those DSLRs and given that 2016 is an Olympic year it's pretty much a sure thing that the next CaNikon sports bodies will be unveiled soon so they can be in the hands of the press before Rio kicks off. But either way, the lack of lenses is the killer. To shoot sports, especially racing, you need at the very minimum a 70-200 zoom (preferably F2.8) and a 1.4x converter for close range work on the track. The Leica 90-280 zoom isn't even due out until the end of 2016. For moderate to long distance you'll need a 300 - 600 mm lens, depending on the track and if you're shooting cars or bikes. Leica has nothing on the board to compare with these. So how is this a sports camera? A 90-280 on a full frame sensor means you'll be pretty hobbled in terms of reach.
Fashion/commercial: Back to competing against the D810, 5DSR, and 645Z. The big guns like the Mamiya and H'blad MF systems are now a factor, too. Not to mention Leica's own S system. I don't see how a 24 megapixel SL fits into a pro's toolkit for this type of work, either.
Video: Maybe this is it. I don't know much about video production, to be honest. But I know the SL offers some stuff when it comes to 4K that has people interested. And you can mount the Leica Cine lenses. I am guessing the A7SII would be the SL's competitor in this area, along with dedicated video devices like the Blackmagic Cinema cameras.
So yeah, I'm kind of fascinated by where exactly the SL is supposed to break into the pro market. I think it'll end up being an enthusiast's toy and it's no accident that the SL is priced similarly to the pre-discount M bodies. It's aimed at the same audience in spite of the "pro" mantra.
