The configure script still reports that one can use --disable-short-tags, but it doesn't work (I have not tried '--enable-short-tags=(off|no|0|false)'). Notice that php -i reports that I have configured and build PHP with the --disable-short-tags option:

% php -i
...
Configure Command =>  './configure' '--disable-short-tags' '--disable-rpath' '--disable-url-fopen-wrapper' '--enable-bcmath' '--enable-calendar' '--enable-debugger' '--enable-dio' '--enable-discard-path' '--enable-embed=shared' '--enable-exif' '--enable-force-cgi-redirect' '--enable-ftp' '--enable-inline-optimization' '--enable-gd-native-ttf' '--enable-magic-quotes' '--enable-mailparse' '--enable-memory-limit' '--enable-mime-magic' '--enable-safe-mode' '--enable-shmop' '--enable-sockets' '--enable-sysvsem' '--enable-sysvshm' '--enable-track-vars' '--enable-trans-sid' '--enable-wddx' '--prefix=/home/matt/com/are/dev/build.nocvs' '--with-apxs=/home/matt/com/are/dev/build.nocvs/sbin/apxs' '--with-bz2=shared' '--with-config-file-path=/home/matt/com/are/dev/build.nocvs/etc' '--with-db3' '--with-curl=shared,/home/matt/com/are/dev/build.nocvs' '--with-dom=/home/matt/com/are/dev/build.nocvs' '--with-dom-exslt=/home/matt/com/are/dev/build.nocvs' '--with-dom-xslt=/home/matt/com/are/dev/build.nocvs' '--with-expat-dir=/usr' '--with-freetype-dir=/usr' '--with-gd=shared' '--with-gettext=shared' '--with-gmp' '--with-iconv=shared' '--with-imap=shared' '--with-imap-ssl=/home/matt/com/are/dev/build.nocvs' '--with-jpeg-dir=/usr' '--with-kerberos' '--with-layout=GNU' '--with-mysql=shared,/usr' '--with-ncurses=shared' '--with-openssl=shared,/home/matt/com/are/dev/build.nocvs' '--with-pgsql=shared' '--with-pic' '--with-png-dir=/usr' '--with-pspell=shared' '--with-readline' '--with-ttf=shared' '--with-xmlrpc=shared' '--with-xpm-dir=/usr/X11R6' '--with-zlib' '--x-includes=/usr/X11R6/include/X11' '--x-libraries=/usr/X11R6/lib'
...

However, it looks like this option is completely ignored:

% cat <<EOF | php
=====
<?
echo "Huh?\n";
?>
=====
EOF

Here's the output:

=====
Huh?
=====