Plone needs a stable, fast, feature complete (but simple) forum add on and it has it in PloneBoard, but it is not used on Plone.org. Why? My guess is that it isn't fast enough (ZODB bloat) or feature complete enough (basics). Plone should convert from Nabble to PloneBoard and in the process get PloneBoard up to speed and make it a class 1 product.

Plone should be able to use Google Gears in order to allow users to edit and/or view content offline.

I want the site to look like this (write in the box) when working in kupu.

http://flowplayer.org/tools/expose.html

As with Zope products and like Plone Portlets, Plone should allow for a configuration form to fine tune product installation and uninstallation. As a simple example suppose a theme wich may or may not install some portlets, and during uninstallation might or might not unregister those portlets.

A tool that will take images of every page in a site before and after migration and then compare them giving a report about any changes

Google wave comes out later this year and really looks hot for collaboration and communications (search youtube or google it for the video presentation).

The wave is meant to be used in websites, but Plone isn't always a typical website (try pasting in html for a youtube video).

We aught to be on top of this (not figuring it out a year or two from now)

Like PloneArticle, as product, shipped by default. Making attachment of images and files even easier to use for end users!

We always need to install textindexng3 to have a better search engine (in case we search word with accent, etc), it could be included in Plone out of the box! would be more simple!

Plone should include a built in job scheduler.
You create a class to represent the job. You then configure the scheduler to execute the run method on that class at certain times with a certain configuration. There should be management screens that tell you when jobs were last run and their result and include the capability to run jobs manually.

There's an excellent JEE job scheduler called Quartz http://www.opensymphony.com/quartz/ something that approached the capabilities of that would be great.

Uservoice is a perfect example - in very little time there are many items and people new to the list likely don't read through them all. Plone documentation is the same way.

Anki http://ichi2.net/anki/ is a great open source flash card program. If it were possible to serve anki cards with a plone module then this would be of great educational use.

End users need a site creation tool. A good example of such a tool is found at http://nces.ed.gov/nceskids/createagraph/ Plone web designers do not have to fear they will lose business. Adobe has pdf a free-use item, yet Adobe is a successful business. Once we have a tool to create our site, we would surely call upon the Plone web designers/developers for powerful specifics.

bringing one of the configurable social networking awarness tools that can be turned on in document actions. In the setup you shoudl be able to configure what 2.0 tools you want to highlight and provide links where needed.

The web is a visual medium, and as integrators, we are very often asked to make plone sites "prettier" by adding more images. We used to write extenders to add images to various content types. Now collective.contentleadimage is available, albeit still in need of improvement. How about incorporating into core the ability to optionally add an image and caption to every content type, and facultatively display that image in different contexts?

PHP is the one of most well known templating and "programming" languages in the world. By leveraging PHP templates in Plone, the Plone development could be possible for far greater audience it currently is.

http://xbsdb.org - the javascript library, which could be useful for portlets development, IMHO :-)
Good for on-line databases, shopping carts, etc.
It allows to operate with data arrays in JavaScript code like with SQL-data.
Both client library and server packages, JSON-based data exhange, and so on..

Could be a version without workflow or some other functionality, but essentially be able to easily migrate an existing site or create a new site on Google app engine.

Make automatic backups of Data.fs available and configurable from the Plone user interface in Site Setup. Currently all recommended backup procedures are external to Plone and have to be setup separately. It would be preferable to have a solution based on Repozo integrated into Plone itself and easily accessible from the admin interface.