Have you heard of JomTube?
Here is what you can read on the extension's website:
JomTube Video Gallery is the most Powerful Video Extension made for Joomla 1.5x Content Management System (Joomla Video Component) which will allow you to transform your Website into a professional looking Video Gallery with functionality that is similar to YouTube.com. JomTube Video Gallery extension video gallery and has been created specifically for the Joomla 1.5x (MVC) Framework and can not be used without Joomla 1.5x as Jomtube is an extension of Joomla and not a stand alone application.
Now JoomlaComment has a plugin allowing you to show comment in Jomtube :) You can find the plugin in the marketplace.
If you have any questions use this forum section.