The new A la Carte will have these dropouts, and I'm pretty damn keen on it to be honest:

But I'm worried that the axle might pull forwards and out of the dropout under load because they're slightly front facing, especially when braking/skidding a fixed wheel. My current bike has track-ends and a tug so it can't go anywhere.

I've asked Salsa if they have any experience of running this setup fixed and they haven't got back to me yet (it's been at least a week, although the frames aren't going to be here for a month or so).

Any ideas or experience with something similar, folks?

They'll be fine for fixed. The braking effort you can generate is nowhere near as much as for forward pedalling.

they're slightly front facing,

How so?

They're slightly forward facing (i.e. not vertical) so that you can get the wheel out without forcing the chain off first like you have to do with a track-end. Like on Konas with sliding dropouts, which I once pulled a (QR) wheel out of when accelerating (but not braking). It wasn't a problem on the Kona I ran fixed with a bolt-up wheel, but my tracknuts were set deep in grooves that had built up over time, like my very own lawyer tabs…

I know people run fixed wheels in old-school horizontal (front-facing) dropouts without chaintugs, so I'm probably worrying unnecessarily.

There's only the tiniest angle at which they are forward facing – I think the "Opened" nature of the dropout (presumably to ease wheel entry/removal) makes it look worse.

As Simon says It'll probably be fine – it's gonna be more tension resistant than the bolt securing the dropout.

And if it's braking you're on about – that will try to pull the wheel backwards, so your concern is unfounded.

I mean braking using the chain… Won't that pull the wheel forwards from the underside of the drive sprocket?

The bolts for the dropout pivots won't need to be done up particularly tight – there's a machine screw that bears directly on the frame to stop those moving (like a chaintug).

I think it's a very neat arrangement and a better solution than the sliders on Kona/P7/Voodoos. Plus look how slinky those stays are. Yum!

my fixie has forward facing dropouts like the second top row here (from sheldon brown):

And i've never had the wheel come out, sure you'll be fine.

Cheers for that pjt, that's what I was thinking – do you skid it? I run 52" on the MTB which skids all too easily off road.

Skidding doesn't put a lot of stress on it especially offroad due to the lack of traction.

The dropouts will be fine.
I assume the bolts and the adjusting thingy will be fine but that's where I would have more concern.
As it's set up for disk brakes they should be fine also.

Dropouts look nice but there doesn't seem to be much in the way of horizontal support (e.g bolts on a voodoo are spaced both vertically and horizontally)

EDITED due to idiot-ness.

[quotethere doesn't seem to be much in the way of horizontal support [/quote]

The bolt that goes horizontally through the dropout assembly and bears onto the frame (near the chili detail) takes care of that – Parts 8 on the diagram in my original link. I hope.