Lightroom: Allow users to define custom metadata

It has come to my realization that a fair number of feature requests could be satisfied simply by allowing users to define custom metadata *without* having to install a 3rd party plugin.

All too often users want to "make notes" about a photo, or associate photos somehow, or record some photo status... Some use keywords and existing IPTC text fields as work-arounds, but what's really needed is a way for users to define custom metadata dynamically, to include types:

- Text
- Enumerated Set of Values (dropdown lists).
- Boolean (true/false)
- Date/Time
- Numeric

This can be done now with plugins like CustomMetadata (although all items are treated like text in smart collections and library filters - a sore point for me), but I think this needs to be built into Lightroom.

PS - *Please* at least fix the SDK to support all data types.

*** - Maybe an even better idea: package a Custom Metadata plugin with Lightroom, pre-installed in Lightroom, so users have the capability AND have a plugin that will also serve to break the plugin ice, so to speak.

Of course users would need to be able to manage custom metadata fields without editing lua files, but dynamic metadata definition is needed by plugins anyway...

Extra special bonus idea: Allow advanced users to use expressions to created derived metadata types, so users could create pixel-count metadata item from width x height metadata, as example. Maybe pre-program that one into the included custom-metadata plugin so users would also have a ready-made example to follow... aspect-ratio would be another popular derived item (cropped-width/cropped-height).