Picking technology you need to also look at where the future of web-technology is going to go, as well as the frameworks in which you are going to need that technology. Accessibility is a serious issue if you pick the wrong technology. I have developed some materials in Flash in the past but this is not accessible to some students with disability. Image-maps were often used early in the creation of web-pages but this is not a disabled friendly technology and so now it is seen less often.
In general the use of plugins such as Flash or Java can exclude possible users for a variety of reasons;
Disability access - some users use text only browsers and so visual only navigation and content cannot be used.
Security access - some users are behind firewalls or do not have administrative access to install plugins.
Bandwidth access - a lot of plugin based technologies need large bandwidth (Java based applets can be very large).
Hardware access - not all students have video or microphone and if they do this increases bandwidth requirements.
The world wide web consortium w3.org has tried to address these issues by creating the new HTML5 standard in which more of the media aspects of the web are actually built into the browser rather than requiring plugins. This presents an opportunity to develop courses in a more customisable and interactive way, even without a VLE, but the cost is going to be a need for much larger development times and a much more technically involved set of authors and author teams.