As far as I know, the bug has been around since sprinting was implemented in Beta 1.8, I think I remember running into it a couple times then.
Nor can I, it appears to be indirectly fixed.
Edit: Never mind, I reproduced it in multiplayer fairly quickly. It appears to be slightly harder to replicate though, and stops in 1-3 seconds.
Yes, I know it is a duplicate. I was giving a better description than "the FOV went boingoboingoboingo", and ways to replicate it.
I do use mods, but I tried replicating it using a plain vanilla client. I tried in various ways, it only seems to occur on internet servers. I could not replicate it at all in single player, or on a locally based server. I connected to a random vanilla server, and as soon as I found land, I was able to easily replicate it. You have to start sprinting within a split second of letting go of shift.
I recorded a video, to show the bug. It took a couple tries at the start, since my FPS was decreased a bit from recording. In the second half of the video, I was showing that you do move at normal walking speed by making a jump that is only possible while sprinting without the bug.
Yes it is, I reproduced it immediately in a 1.5 vanilla server.