First, PLEASE help with these unrelated questions if you can (I'm somebody who actually answers questions others have when I know how):
http://forums.movabletype.org/2009/08/different-category-entry-list-in-category-archive-page.html
http://forums.movabletype.org/2009/09/cant-log-in-to-comment-with-ie7.html
That said, onto the actual point of this thread, MT5.
I love the idea of organizing "websites" as a series of "blogs," rather than just having a series of unrelated blogs in a given MT install. It makes perfect sense. Nevertheless, it's completely useless to me the way it's currently built (I'm using beta 1).
I need to be able to post a given Entry into multiple blogs. The same goes for Assets. The way I organize my website right now is that each "section" of my website is a Category. I'd rather be able to make each section of my website a "blog." But if I have something I want in the "Press" section AND the "Employee Free Choice" section, for instance, I don't want to have to post the same content twice.
That's my biggest complaint about MT5. It's a much better way of organizing "blogs," but it's pointless for me unless content can be cross-posted across the website in a way that can scale. No, it's not an option to simply use the blogs=1,2,etc. Categories are changing all the time, and I'm managing multiple websites, with the people directly modifying them having little web experience. I need something that's simple to change for them, rather than relying on me to go in and change templates.
If this is unclear, I can clarify. Mainly, this is in hopes that voicing this will set a direction that allows me to actually use MT5 when it comes out. Because right now, even if bugs were fixed, I wouldn't be able to use it because of these problems.
Reported on Movable Type 4.3

Wait for Beta 3. Beta 3 reflects a lot of criticisms about the first betas and is supposed to have a lot of UI and functionality improvements to make MT5 more intuitive. If you still have problems with Beta 3, post your criticisms both on the mt-dev mailing list and in the bug tracker. They're looking for a lot of serious criticism of MT5 right now, so if you want to get concerns addressed, they're all ears right now.
@elicash, I have some of the same thoughts, although I worry that I am not well-versed enough in the richness of the template tags available for facilitating the kind of cross-website/blog sharing of system objects that you are referring to.
Can we hear from developers who know some of the best practices (if they exist?) for facilitating this kind of easy access to objects across a Website/Blogs? Are their reasons to avoid this arrangement? Or are there Website architectures more conducive to this kind of sharing that take better advantage of categories and tags within a Website/Blog?