Here is my shot:
http://bitbonk.spaces.live.com/blog/cns!E17530AA6EFF7871!177.entry

1.) Shader support for bitmap effects.
2.) Add the ability to place 2D controls on 3D surfaces.
3.) DWM integration.

adding own words to spell dictionary

Ability to specify names (x:Name) for controls inside a ResourceDictionary.

databinding flowdocument would be very sweeet

my shot at this
1> ability to obtain collection of inline textchanges
2> text search/find

i second wesley :)

Ability to add editable fields in XPS documents.

2D - "pixel-precise" graphics for lines, rectangles, etc. with no antialiasing applied for horizontal and vertical lines/segments.

I agree with Wesley. keep up the Good work WPF :)

I've got loads:

Calendars: date picker, time picker, month picker. With nullable support.

NumericUpDown/Spinner.

Masked text input.

DataGrids. And less hand-coding ListViews for common tasks like sorting and check marks.

Vista task dialog and wizard support.

More media support (audio & video from streams, feedback for things like audio visualizations).

Open up the spelling & hypenation API. Allow exceptions to be defined by the user (like earlier versions did).

Proper font dialog (i.e., one that DOESN'T skip CFF OpenType fonts like WinForms does), augmented with OpenType feature selection.

Faux small caps for fonts that don't have OpenType small caps. (Like Word and IE do, but better.) Should probably be extended to all caps and all lower case.

Tear-off and docking toolbars with user customization support (à la Office and Visual Studio).

More built-in ValidationRules.

PdfDocumentWriter next to XpsDocumentWriter. Dito for document serialization.

Loose XAML with scripting support.

Control over sub-pixel ClearType vs. gray scale anti-aliassing (for generating, say, bitmaps).

more speller language msi's

mask textbox
more speller lang support

Increase support for additional speller languages.

Enabl elements in RichtxtBox