Here are my running observations on Tiger on a 15" Aluminum PowerBook, 1.25Ghz, 1Gig of RAM, 60GB 7,200RPM HD (Enhanced) with Illuminated keyboard and Superdrive.
The install went less than perfect. The DVD creates a Kernel Panic upon boot. "Drivers were not found for PowerBook model 5,2". This why you may need to have FireWire, you will need to install manually from, say, an external drive or another partition. Also, I believe that it will come out on multiple CDs, and with your machines as a DVD if you have a superdrive (as Panther did for me).
First Observation: DASHBOARD
Is incredible. The simple implications and applications are astounding. It is what Expose was really invented for. Imagine taking Expose, the ability to "watch" multiple windows on your desktop in real-time, and add to that, the ability to "work" in those windows on multiple applications an processes. It is a tool, something that I will actually use.
Second Oberservation: POWERBOOK SPECIFIC ENHANCEMENTS
Strangely enough, though this DP preceeds the ones even demoed at WWDC, yet it is feature rich with little, yet critical, improvments that many of us in this forum have been asking for. For those that submitted bugs to Apple, they were listening. Could be that they were compiling these improved for quite some time to put into Tiger. Panther to many, is a complete and stable OS, to others it's still incomplete, with that 75% done feel ( I agree with this, networking is incomplete, MetaData needs to be implemented). I believe that Tiger will be to Mac, what Win2K Pro was to PC's.
Keyboard Illumination and auto light level sensing are now acurate and much faster and response. Keyboard illumination used to get "stuck" off for me when a bright light, like a lamp, was shown on the keyboard. This is fixed. And I actually use it now.
With USB Soundsticks, Logitech MX700 mouse and Logitech control center, sound does not dissapear when waking from sleep.
Second, when put to Sleep from menu, the pulsing light is subdued. With lid closed, light pulses deep and bright.
When copying files, Tiger, displays new detailed information with having to expand the small triangle button, that's gone.
Safari IS faster. Pages render "instantly". Dave spoke of this perceived enhancement. Page scrolling is smooth, finally.
Quicktime player is now Cocoaized. Movies resize in realtime. Expanding the window (green button) now makes the movie expand to fill the screen and back again to the original size, as it should have done.
Other info to follow.