Well, first let's note that Drupal 6 has improved handling of teasers. I've only poked at it a little – I won't have any operational D6 sites until more key modules get updated. But while the new teaser handling doesn't perform every circus trick we might want, it's a nice addition, and I heap great thanks upon the developers.

As for Views: Actually, I think you're hinting at what IS a solution, at least for some setups. To give a node multiple teasers for multiple uses, I'd think you could add fields using CCK – "Teaser 1", "Teaser 2", etc. – and then for each Block or View, just specify which teaser field to use. (Sure, you also have to go and input those multiple unique teasers for each node, but I don't see how any solution could avoid that hassle; after all, those multiple teasers are the goal.)

But I think you're looking for something a little different: automatic teasers (by word-count) for the node, with the ability to set the word count by Block or View. That'd be nice as you could vary teaser length by use, without having to manually input multiple teasers per node. Unfortunately, I don't know how exactly you could do that.

But as long we're on the topic, some other teaser tools:

There's some module that lets you specify teaser length by node type, so you could have Pages use a 100-word teaser, Stories use a 500-word teaser, etc. That's still not what you mention, but for some people it may have interesting uses. Unfortunately, I'm drawing a blank on what module it is – Teaser Management, maybe?

Content templates also let you modify teaser output – though again, I haven't yet properly looked into the function.

Finally, there's CCK Teaser Field, which lets you take any CCK field, and specify that as the default teaser field. (I don't know how that'll clash with the Node Teaser module.) As I've long had odd teaser troubles with this site (and strangely, not with other sites running on the same Drupal installation), I've been eyeing CCK Teaser Field as my possible savior: ditch Node Teaser, create my own new teaser field, and let CCK Teaser Field specify that as the universal teaser field for my posts. I just haven't yet gotten around to trying it out and seeing whether it solves my problems, or even works at all!

So there's no über-tool for doing everything we might want to do with teasers, but there's the next best thing: plenty of smaller tools to mix and match. I need to get on top of these more.

Thanks for the message, dagomar!