I noticed a few weeks ago that some of Github's recent blog photos were really big.[1][2][3][4][5] They range from just big to "Are you kidding me? I can watch this slow-loading in real time even with a good connection..." big.
Given how much they know about the web, I'm guessing that it's deliberate, not just some grandparent forgetting to resize a photo before uploading it to the web. Either way, I think it's way too soon to be using full-size photos on the web without resizing them.
[1]: https://sphotos-b.xx.fbcdn.net/hphotos-snc7/326049_101509382...
[2]: https://s3.amazonaws.com/pixelhub-heroku-test/designs/design...
[3]: https://s3.amazonaws.com/pixelhub-heroku-test/designs/design...
[4]: https://a248.e.akamai.net/camo.github.com/859292fb3b177112fe...
[5]: https://a248.e.akamai.net/camo.github.com/352f3e89269c0d18c4...