I think what is being requested here is that when you install the unstable version of TVHeadEnd under Debian Wheezy using the instructions on the page at http://tvheadend.org/projects/tvheadend/wiki/AptRepository we'd like to see transcoding support enabled by default, which apparently it is not at the moment for some reason - there is a discussion of this at http://tvheadend.org/boards/5/topics/14344 and the third post down notes that "It seems that the wheezy build was not compiled with transcoding enabled." That is what some of us would like to see corrected, me included.
The problem with installing deb files is that they are never automatically updated, for example when you do sudo apt-get dist-upgrade, whereas when you can add a repository in /etc/apt/sources.list then any updates are found automatically.