In the current version of Inkscape seems not yet possible to embed SVG fonts (see also here a little example).
In 0.48 Release Notes:
There is a known limitation where the list of glyphs in the dialog are not yet rendered in the selected font, but still in the system font
In 0.47 Release Notes there is a more detailed explanation of the limitations:
As a SoC 2008 project, JucaBlues implemented initial parsing and rendering of SVG Fonts. You can design fonts within Inkscape, but using them to render text on the canvas is not yet supported. We are waiting for libpango to implement proper support of the user-fonts feature.
The render of SVG Fonts is not supported by Firefox or Internet Explorer, and Inkscape Wiki tell us that:
SVG2.0 may replace SVG fonts by WOFF
(let's wait and see)
At the moment, following this tutorial I was able to embed a WOFF font in SVG:
width="100%" height="100%" viewBox="30 40 340 135">
<title>WebFont Template for SVG</title>
src: url("indie_flower.woff") format("woff");
font-family: "indie_flower", serif;
<text x="200" y="80">http://schepers.cc/svg-webfonts</text>
<path id="curve" d="M75,170 C150,140 200,140 250,160" fill="none"/>
<text><textPath xlink:href="#curve">Google Indie Flower</textPath></text>
The font was copied locally following this url (get from here) and obtaining the download link (conveniently renamed into "indie_flower.woff").
The SVG file uses a local font and renders well (tested with Firefox 34, Chrome 39 and Internet Explorer 11 under Windows 8.1). Using a local font I cannot link the SVG file, you have to settle for a screenshot:
Unfortunately (see above), Inkscape at the moment is not able to render it and use the default font.
At the moment...let's wait and see.