I hope at the event in a few weeks we get software updates from Apple for OS X Yosemite.
iWork
As seen in this image from the Yosemite GM build's trackpad settings video, the iWork icons in the dock have new icons and Pages (shown here) will be getting a new toolbar with the release of Yosemite.
This indicates the iWork apps will definitely receive updates for Yosemite, iCloud Drive, Handoff and UI changes if only to update the toolbars and icons.
iLife
The iLife suite was updated last year, but their interfaces are outmoded in the new, flatter Yosemite look. If iMovie and Garageband are updated to match Yosemite's UI, they will likely get new icons as well. They could also support iCloud Drive.
The UI changes will probably be sparse and limited to removing gradients and perhaps adding a touch of translucency.
With Photos, Apple has two real options:
OPTION 1 - iPhoto will receive a small update for Yosemite, including limited support for iCloud Photo Library
OPTION 2 - Apple will leave iPhoto and release Photos.app for Mac in Beta. Users will have the option to test Photos ahead of its public release.
I hope Apple chooses Option 2 and gives users the Photos.app in beta ahead of the launch in a few months.
I also hope Apple indeed does update iMovie and Garageband's icons and UIs to flatten them and keep them consistent with Yosemite, supporting iCloud Drive, and like iWork maybe adding Handoff support.
Exciting times ahead!
iWork

As seen in this image from the Yosemite GM build's trackpad settings video, the iWork icons in the dock have new icons and Pages (shown here) will be getting a new toolbar with the release of Yosemite.
This indicates the iWork apps will definitely receive updates for Yosemite, iCloud Drive, Handoff and UI changes if only to update the toolbars and icons.
iLife
The iLife suite was updated last year, but their interfaces are outmoded in the new, flatter Yosemite look. If iMovie and Garageband are updated to match Yosemite's UI, they will likely get new icons as well. They could also support iCloud Drive.
The UI changes will probably be sparse and limited to removing gradients and perhaps adding a touch of translucency.
With Photos, Apple has two real options:
OPTION 1 - iPhoto will receive a small update for Yosemite, including limited support for iCloud Photo Library
OPTION 2 - Apple will leave iPhoto and release Photos.app for Mac in Beta. Users will have the option to test Photos ahead of its public release.

I hope Apple chooses Option 2 and gives users the Photos.app in beta ahead of the launch in a few months.
I also hope Apple indeed does update iMovie and Garageband's icons and UIs to flatten them and keep them consistent with Yosemite, supporting iCloud Drive, and like iWork maybe adding Handoff support.
Exciting times ahead!