Yeah, Apple sort of misses a good opportunity with having the user's Trash in the Dock, therefore accessible to all apps.
Seems to me that a lot of these issues potentially all have a common denominator. I think the issues people have with the Dock, metal windows, quitting when closing a window, the Trash icon, etc. can all be resolved in a rather elegant way all at once. Apple hasn't gotten their collective act together with regard to the Human Interface Guidelines. I having trouble explaining this as I write, but it's like there's one word, one concept that glues them all together (plus some third party apps with them) that would collect all these inconsistencies into a single category of use, behavior and appearance. Something beyond the "digital hub" container, something more flexible and inclusive.
It's like iTunes, iPhoto, iCal, the Panther Finder and maybe even Mail are all indexes. That is, they don't create content per se, they manage them. (Mail being sort ofin between: it both manages and creates content.) You could probably say the same for Safari, but probably not for iMovie or iDVD right now. If you had something like QT's favorites in a single app, you would be closer to a true "iMovie" in the same family as iTunes from that perspective. The index/management apps all could use a (primarily) single window UI that uses the metal appearance, uses the quit-on-window close behavior (preferably with a modified close widget sort of like the dot for modified files is a warning), they should all use the Dock Trash as their common receptacle, and all that.
It's funny, Apple's HI teams are working on actual projects rather than working in an ivory tower. It seems to have its benefits and faults. On the one hand, I think Apple has introduced some nice new ideas to some apps' user experiences. On the other, it's like no one is keeping everyone on the same page with regard to these ideas. It's like some teams find these things out when we do, but at least they see it in action, they don't just read about it in some white paper.
As for the Dock, the original topic at hand, well, I know since I started using Panther, as as I use Expose more and more, I've started leaving my Dock hidden most of the time since I don't minimize windows much any more, and I open most apps I need on startup and go through the much more convenient Finder for the others. I thought the app switching via the Dock was rather elegant if too subtle I suppose. Losing the Dock in the ned for what I consider a more direct way of working is rather nice. The Dock might have an identity crisis, but maybe it can gain a new identity. Maybe we'll see the return of a split Dock a la NeXT and OpenStep so you only use the half that's useful to you. Maybe we'll see the return of Docklets as the menubar gets more crowded for oft-used functions (though I took the volume and eject menulings off some time ago). Maybe the Dock can incorporate more clipboard-like and shelf-like functions for temporary storage and management (another management app?

) of all these floating and often too-hidden bits of data we juggle all the time. Maybe it incorporates multiple workspaces and stores workflow settings and arrangements (like the snapshot script from Apple's Applescript site). 10.4 could be a real opportunity for the Dock to get a major overhaul like the Panther Finder (which will hopefully have some important improvements of its own).