It is correct that uploading larger files is possible, however not in all ways. 
When using Apache with mod-php it's not possible to upload a file using stdin 
that's larger than the memory limit, probably because the script will get invoked 
only as soon as all the post data is available. Thus when using client side 
methods like plupload, it's impossible to upload files larger than memory_limit, 
which is quite annoying.

As said by Ilia:
We no longer load the uploaded file entirely into memory. So I think it should be possible to upload a file that is > than the memory limit

I was about to open a bug for the same issue when I found this report.

http://www.php.net/manual/en/ini.core.php#ini.post-max-size states:

“If memory limit is enabled by your configure script, memory_limit also affects file uploading. Generally speaking, memory_limit should be larger than 
post_max_size.”

To me, the phrasing is misleading as it implies that file uploads (<input type="file">, multipart/form-data, $_FILES array) have to fit into memory_limit. That is 
probably not the case. It is my understanding that the second sentence from the quote only holds true for large application/x-www-form-urlencoded POST requests 
(without file uploads) while the first sentence is more or less incorrect/superfluous.

Other mentions of this issue:

- http://stackoverflow.com/questions/3651141/in-php-settings-should-memory-limit-upload-max-filesize
- http://stackoverflow.com/questions/5106871/relationship-between-phps-memory-limit-upload-max-filesize-and-post-max-filesi