For me, it is about being able to do the basic professional tasks in an easy to learn and accessible way. If you have such a device, it will get used by media professionals. If this happens, the media itself will notice and talk about.
Until now, the devices were for the technical creativity by developers and powerusers. Now the time has come for the device to become a tool in itself, a professional tool. The device itself may therefore not be a hindrance anymore, but must be the enabler.
To precise the answer, I prefer UseCases to poetry, though :-) Therefore, the following list shows my expectations and ideas for Creative Media Editing & Sharing on my device. The scope varies between abstract usecases giving a general idea and technical details that might be first steps in the desired direction.

Pictures: (Looks like the N900 is on a good way)

• Take pictures
• Crop, rotate, resize them. Remove red eyes.
• Transfer/Upload using various service
• Be able to work with pictures from external devices, either by accessing the storage medium or by transfer over USB (needs USB OTG or USB Picture Transfer Protocol).
• Print pictures on the go with various printers (using PictBridge?)
• Gphoto2 for Maemo5?
• Allow automatic workflows (auto-tag and upload directly after capture)

Audio:

• Record audio in mono and stereo in acceptable quality (as a dictaphone or for streetinterviews for radio broadcast) using inbuilt microphone or external mic.
• Support various standard compressions/codecs.
• Allow minor editing of recordings (Cut/Delete, Merge, Volume adjustments)
• Transfer/Upload using various service
• Allow audio streaming (dyndns? bandwidth/proxy?))

Music:

• My weak point - I'm accoustic guitar and voice :-)
• However, I guess that a) nobody wants to replace instruments and b) input/control is too limited on such a device to create electronic music (multitouch, space for two hands, pressure sensitivity). Skip that.
• Perhaps as a recording device for raw sound (MIDI over USB) or as a simple multi-track recorder to catch a jam session.

Video:

• Take video in at least SD (480i, 576i). Enable digital zoom while recording.
• Store using a standardized "modern" codec and container (H.264/MPEG-4 AVC), so that playability is guaranteed and transcoding unnecessary.
• Allow USB OTG/Host/Mass Storage (Include appropriate adapters/cables in package...)
• Allow minor editing of recordings (Cut/Delete, Merge, Volume adjustments, add 2nd audio track)
• Allow transcoding to low bandwidth formats?
• Transfer/Upload using various service? (Bandwidth)
• Allow video streaming (dyndns? bandwidth/proxy?)

From the various N900 reviews, specs and videos that I've seen so far, I guess that in many areas, we are "nearly there". Or at least we can really concentrate on the software, as it looks like the hardware is not the limit anymore - no excuses for missing software... (except perhaps the current state of development tools and environments for Maemo...but that is another story which I hope Jaffa will tackle at the summit :-)

I also agree with the position of allnameswereout in terms of the limits simply due to screen estate and UI possibilities - there is no need for full-power editing madness effects etc. However, the base elements of the initial workflows should and can be covered.

I guess that with this thread, we are in the" Instant and fun media editing/remixing/sharing" topic as originally announced - however, don't forget two other "media types": text and drawings (think xournal).

• What about scribbling a handwritten something over a picture just taken before uploading it? (my printer, an Epson PX800FW, has such a function using the scanner to overlay a handwritten note over a photo to be printed)
• What about a sketching app with a finger-scrollable canvas and a very simple UI? (my kids LOVE to scribble on their N800 and my N810 using Sketch - the canvas is however too small and doesn't scale to fullscreen)
• What about simple layouting/DTP? A scrollable canvas in A4/Letter/10x15cm, a method to write and position some textboxes, a function to overlay a few images or video stills. Then save it in PDF or print it.

In finishing, I return to the abstracter philosophy... always bear in mind the "limits" of creativity - I'm highly skeptical about the amount of / energy for creativity in the general population. Letss perhaps rather talk about cre-activity, a term I like to use as a placeholder for "being entertained while still being able to add minor input / low input activities". So, for our ideas of usecases - let's keep it simple, but complete and usable. This is what made the iPhone a success. With all our fascination for hardware and software engineering , don't forget the human end users!