[Joel]

Multiple canvases are indeed a feature of OmniGraffle for iPad, and while there is still work to be done for future versions (things like Image manipulation and Notes and Actions, etc.) the round trip from desktop to iPad and back should be non-destructive to existing documents, with one caveat, which is being able to edit Rich Text for different strings of text in a shape's label -- Currently on OmniGraffle for iPad, editing the style of text does so for all the text in a shape's label.

That said, we don't know for sure what size limits will come into play on the iPad itself, both physical dimensions or filesize, and when we run into problems we'll see about getting them fixed as best we can, but we more or less have to wait until tomorrow.

Finally, as for DropBox compatibility, it remains to be seen, however we can count on being able to handle OmniGraffle documents via email as well as downloads from Safari on the iPad (so long as they have the proper file extension when zipped), so I'd take an educated guess that if DropBox hands off a .graffle or .gstencil or .gtemplate, the iPad OS will properly ask if you want to open it in OmniGraffle, and copy the file to OmniGraffle's documents directory.

Hope the above clears some things up.