Well, I'm still looking forward to this keynote, however I don't expect anything that would surprise me. I think that the Mac Pro is a missed chance, because a lot of pro users that really needed the versatility of a desktop computer already switched to PC. I appreciate they have tried to do something new with the trashcan Mac Pro, but they should have act much quicker when they realized the overall design is not good. This waiting for a profesional desktop computer clearly destroyed the Apple's reputation much more than admitting the design was a mistake.
Just look at current desktop computers. The case design practically haven't change since 90s. And of course knowing Apple it seems that one of the reasons why they have designed the trashcan Mac Pro was to lock down the upgradability.
So I expect they will show a modular system that is gonna be locked down to use just some Apple-approved components, not yet ready (available in 2020) with a $4000–5000 price tag.
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What I would love to see is an iPad-focused iOS release. I would love to use iPad in my webdevelopment workflow but without the mouse support and better filesystem, I just can't use it for anything related to my work. It's really a shame I don't see any reason why I should buy iPad Pro over the current iPad Air. I bought iPad Pro 9.7 because of the Apple Pencil and keyboard support, but iPad Air also supports it now. Ok, current iPad Pro is a nice design, has incredible specs, but it can't do much more than the base iPad, which is like: whaat?! So I hope it will change with this release.