I frequently use cmd-E in all my Mac applications, so I'd love to see this implemented for the message list.
Here's a category method I use myself for the web view (since the writeSelectionToPBoard doesn't seem to work):
- (IBAction)copySelectionToFindPboard:(id)sender
{
DOMDocumentFragment* selection = [[self selectedDOMRange] cloneContents];
DOMNodeIterator* iter = selection ? [[[self mainFrame] DOMDocument] createNodeIterator:selection :DOM_SHOW_TEXT :nil :YES] : nil;
NSMutableString* str = [NSMutableString string];
while(DOMNode* node = [iter nextNode])
[str appendString:[node nodeValue]];
if(![str isEqualToString:@""])
{
NSPasteboard* pboard = [NSPasteboard pasteboardWithName:NSFindPboard];
[pboard declareTypes:[NSArray arrayWithObject:NSStringPboardType] owner:nil];
[pboard setString:str forType:NSStringPboardType];
}
}