udev and the 'hotplug' package

[marlin9@gmx.ch]

Here is the second question ;)

Nowadays (testing/sid) package 'hotplug' is also provided by 'udev'.
However, they seem to be distinct packages excluding each other.
So it seems to be possible to have hotplug instead of udev ? 
Am i right this is a provision for older (2.4) kernels, and would be completely 
pointless with a 2.6 kernel and udev already working ?

I think i still puzzle about some confusion within the vivid kernel transition process.
I remember it was possible (and even recommendet, in the beginning) to have both 
packages installed altogether, and purging 'hotplug' somewhere later, left some  
artefacts in /etc/hotplug which i deleted manually, according to the docs. 

I can see other packages drop files in /etc/hotplug, like libgphoto or libsane, 
but they also add udev rules which seem to provide the same functionality.
(I don't know what's the 'blacklist.d' directory for, though, and if udev has that 
feature  too.)

I also notice that /etc/hotplug is created only by these (secondary) packages,
dropping their hooks in, without them the folder would not exist at all since 
there's no 'hotplug' packages installed (anymore).

AIUI this kind of circumstance is just to allow to run older kernels as well as new 
ones, in the same environment ? (And how long should this be continued ?)
Or did i just miss some other important point ?

Regards, 

mare