- Try to avoid talking about time-sensitive details (explicit reference to dates/places, jokes/references to items in the news, etc.
- Avoid "off-the-record" type remarks: things that are probably OK for the moment, for that audience, but can be harmful for an online audience. Revealing confidential strategic information will prevent you from posting the video online, jokes/remarks can backlash when taken out of their presentation contest.
- This might be a bit hard: trying to avoid references to previous speakers.
Speech on video? Think of the day after
If your speech is recorded on video, think about online viewing that will start the day after, and lasts forever, especially when you want to use the video for promoting your business for example. In your speech: