Woot! My very first SVG icons.

Unfortunately, Posterous can't handle SVG conversion (lol). So if you wanna see the SVGs, poke meeeeee.

Icons inside the applications themselves should be simpler and more graphic rather than realistic, like so:

Update:
BLAH! So it turns out WPF can't easily handle raster images, so the in-application icons cannot be the style shown above. The style shown above requires pixel art...which is, by nature, raster.

I also tried redoing a raster in pixel style (eg. 1x1px squares...) but that still doesn't look good, and apparently takes quite a bit of processing power to render.

Vector vs Raster Icons at Small Sizes (original file cabinet icon)

More details on why this happens can be found in this great article. There are lots of comments from what I presume are non-pixel-art-creators that still manage to miss the point. Since comments aren't working there anymore (lol the post IS 7 years old...), here's the point that the comments in the article miss...

Pixel Art Requires a New Level of Abstraction
This is something that doesn't seem to have been covered in the comments, that anyone who does pixel art at the tiny sizes it's ideally suited to knows.

When you go to 48x48 and below, the level of abstraction required to make an icon APPEAR like something to the naked human eye entirely changes the way an icon has to be designed.

Simply shrinking a detailed high resolution vector into 48x48 and lower doesn't work because even if the vectors were somehow able to magically keep their detail and proportion, our eyes start to interpret things differently at those sizes and below.

Tiny sizes demand visual abstraction that does not scale, and pixel art is the way to go with that. Sure, you could draw it in vectors, pixel-art style, a 1x1px block at a time, but it would take a quite a bit of processing power to render, and still doesn't look as good (see above).

Guess I'll Make 'Em Fancy Vectors
Sooo... in-app icons will have to be fancy and realistic too. Oh well, at least there aren't many of them. At least, I'm planning them not to be. Not too fond of icons inside applications that scream LOOK AT MEEEEEE.

Here's a LOOOKATMEEEE icons so far. ._.

Final 'now-that-I-can't-use-pixel-art' file cabinet icon.