X11 still uses /dev/mem ?

[Nix]

On 17 Feb 2010, Adam Jackson said:

> On Tue, 2010-02-16 at 10:30 +0200, Nameer Yarkon wrote:
>> Hi,
>> 
>> Does X11 still uses /dev/mem to directly manipulate the physical memory ?
>
> strace would tell you.  The answer is "it depends" though.  On Linux,
> most memory access goes through the PCI BAR resource files in sysfs, but
> there are some situations where we still have to use /dev/mem.

Am I right in assuming that pretty much all of these are UMS-related? 
i.e., in KMS the only thing now stopping us running X as non-root at
long last is the input-device-revocation problem?