Hi, as far as I understand the docs there is no limit on the tweets for stream/filter. However, as a regular user you can only follow up to 5000 users (but you should get all of their tweets). If this limits you, you can apply for "Shadow-role" to up this limit to more users (20k afair).
To answer your question: thousands of tweets per hour should be doable, as long as you don't need to follow more than 5000 users. -d -- Twitter developer documentation and resources: http://dev.twitter.com/doc API updates via Twitter: http://twitter.com/twitterapi Issues/Enhancements Tracker: http://code.google.com/p/twitter-api/issues/list Change your membership to this group: http://groups.google.com/group/twitter-development-talk