I would say that this will, for the most part, benefit web developers as it will put everyone on the same page.
The Mac 1.8 gamma was a better match for print output but it's increasing irrelevance makes it only natural to increase the gamma for better video/image viewing.
Gamma explained: http://www.thehelpful.com/gammaexplained.html
γ is mainly a way to align the metric in our color space with human perception: humans adapt to varying light levels, even in small areas of the visual field, and our judgment of color differences is relative (i.e. relative to magnitude, logarithmic) rather than absolute (linear).
Any operation that requires interpolating between arbitrary colors (e.g. image rotation, scaling, or compositing with transparency) will have errors introduced by any γ ≠ 1.0, so careful image processing applications should convert to γ = 1.0, perform whatever operation, and convert back, but in practice none of them do, because with sufficient pixels, especially if they're mostly opaque, users don’t know they should care.
But storing colors in 8-bit color with γ = 1.0 would be a disaster, because we’d be devoting half of our storage space to the very bright colors, while leaving the dark colors only a few levels of distinction: the darks would end up extremely noisy.
Incidentally, this last is the reason that digital cameras, even though they collect 10 or 12 bits per channel of data, end up with noise in the blacks: cameras gather photons and store them linearly, meaning that the light parts of the image are silky smooth because we can make many fine color distinctions, but not the darks. Hence the general advice to “expose right.”
Soon enough, we’ll just be storing and manipulating images in γ = 1.0 floating point, and thereby get the best of both worlds: operations are technically linear, but the encoding space is assigned logarithmically.
There are plenty of sites where you can learn more about camera noise.
This is an incredibly confusing subject, thanks to the overlap of gamma as an encoding technique with all the other issues around color management. Poynton's Gamma FAQ is one of my favorite resources ( http://www.poynton.com/GammaFAQ.html ), but even after five years working on image processing software I still have to make an effort to wrap my head around it all.
I'd prefer the base2 display, as I think it's confusing for example when exchanging USB keys with Windows machines. Furthermore OS X now is inconsistent with file size display, because not all OS X programs use base10 at the moment (for instance QuicktimeX).