So, odd person that I am, and replacement Touch (oh, the joy) in hand, I wondered if it might be possible that the code for adding in our own fonts was there, even if the choice doesn't appear on a menu yet.
It is!
Attach your Kobo Touch (running 1.9.4) by USB so you can manage it as a device. Create a "fonts" directory off of the root. I don't think it actually matters if it is Fonts or fonts. Copy and paste the fonts you want (TTF or OTF) from your computer's fonts directory into the new fonts directory on your Kobo.
After you eject the reader, the fonts should appear in the "Aa" menu. I have added two so far, but when this feature was announced, we were told we could have 6 I think. It may be that the default fonts count toward whatever limit we have. A littke experimentation will tell

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I'm a serif fan for reading, and so far, I'm loving palatino linotype the best. OK, I'm loving Bookman Old Style the best now.