Go to the component installation area of Joomla. Click the Components tab. You'll see a list of installed components included version numbers and dates.
I never noticed that before. It says I'm already using 2.4.6. That seems to be the latest release for Joomla 1.0. So I'm assuming I don't need to do anything.
Yes, 2.4.6 is the latest for Joomla 1.0 and that will never change. Development for the 1.0 version stopped in March 2009. Unless you upgrade your site to Joomla 1.5 (which you should REALLY do), you will never get any new features to DT Register.
Easier said than done. It's a very huge site and many of the components can't be found for 1.5. I'll have to see which components, the church could possibly do without. I'll probably wait for 1.6 and then build a new site. By then they'll probably be ready for a new look anyhow. I purchased the template but changed the design completely. The site is 8 or 9 GB in size.