I would say they'll be looking to round up the widely reported issues with 10.5.3 ... and continuing to ignore the ones that I've reported, some, several times
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I can't browse FTP shares in the Finder GUI further than 4 directories down - attempting to causes the share to disconnect. No problems on Tiger, via the CLI or on Vista by boot camp.
On wake from sleep the colour calibration sometimes reverts back to the nasty default 'Color LCD' - until I visit the Displays prefpane, at which point it wises up.
The iTunes dashboard widget does not work, and it never really has. On its backside the 'playlists' dropdown simply does not drop down; the shuffle 'button' usually does not work, and can bring a crash notification, although this is not as easy to reproduce as it was under Tiger.
The sidebar does not function correctly in open/save dialogs - items should not be highlighted as active unless they are being displayed, OR clicking them should always bring them into the view.
Stacks still 'randomly' stop responding to clicks - right now this is fine on my machine but yesterday it was easy to reproduce.
The menubar does not necessarily reflect the frontmost app. This is most easily seen with Entourage's desktop notification, but happens enough with Apple apps to be considered an OS issue. It never happened in Tiger or prior.
The clock is still wrong due to timezones and EFI after restarting following a Windows/bootcamp session. Vista updates immediately on startup; Leopard doesn't seem to have a set time for updating, and reconfirming that you want to sync with a server does not fix it either - manual fix ftl, if you'll excuse the WoW parlance.
Then there are things like the repeatable Mail crash that was reported, and repeated after 10.5.3's release. I hope I can tick a few of these off in a few weeks' time; really glad they are moving things along
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