Theoretically it would be better if install.txt would be generated from the manual IMHO. There is a maket target for it, which filters the install part through lynx to get a text version. It should be fine it this install.xml is adjusted to the new install stuff - to use the new entities pointing to the new files (with windows only information if only used to generate the windows instructions).
OK, I've fetch the install.xml and I've upgraded it to the new install section. The output is here: http://testes.aborla.net/install.txt
I have to agree with you that it could be better if the install.txt was generated from the manual, as it would be easier to have the files in sync. But I think the generated file is too big and hard to read. Maybe we could just remove the text that is in the install.txt file and put there a link pointin to the manual :)
There are a lot of people actually using the distributed install files to install PHP. Note however that there are two files:
php-src/INSTALL (for compiling on unix like systems) php-src/win32/install.txt (for binary packages on windows)
Note that there is no single install file containing all platforms (like the txt you built). It would be more than good to investigate how the INSTALL and install.txt files can be built from our manual sources (that is only including platform specific instructions in them and no windows building instructions, etc)
Goba