Well, 1.0 was the best version they could get at the time they released RH8. Seeing as 8 is not the current version, I doubt they'll do much in the way of updating packages. They might release fixes, but prob'ly not much else.
You can download the latest version from Mozilla.org and install. I have 1.5 running on Fedora, which came with 1.4. It's pretty easy to do...
Download the .sea.tar.gz for the version you want to a directory called downloads in your home directory.
Open a terminal window and cd to downloads.
Run "tar -xzf mozilla*gz". This will unzip/untar the file, and create a directory called mozilla-installer.
"cd mozilla-installer" to move into the new directory. Then, run "./mozilla-installer". If you run it as root, you can install it so any user can use it. If you run it as a user, you can only install it into your home directory, and only you can use it.