Just a small note on user cases:
The lowest common denominator of Joe Schmoe out there (that can be expected to use Inkscape) is probably the Windows user who's only familiar with 2 programs: an internet browser and Microsoft Word. That's it.
He's neither a webpage designer nor a raster graphics master. He's the type who (very regretfully) takes 2 MB photos, sends them as is to you by email, and doesn't even know (nor care) that he's doing it wrong (unfortunately, this is also about 90% of the people I've worked with...).
Such a person's notion of copy/paste is: - Copy text. Paste in Word file. - Copy image. Paste in Word file. - If the image is modified, delete the original image and paste the new one in. - They don't expect anything they've pasted in to disappear when they move the file around or send it to their family/friends/boss.
(and yes, that level of user may come to use Inkscape. I often use Inkscape to do charts for work, it's handy)