New fonts in FCPX 10.1
In addition to the older built in fonts for FCPX/Motion, version 10.1 provides about 40 more fonts:
AvenirBlackOblique.ttf
AvianoSansBold.ttf
Bank Gothic Light.ttf
Bank Gothic Medium.ttf
BasicCommercialLTCom-Bold.ttf
BeaufortPro.ttf
BebasNeue.otf
Bradley Hand Bold.ttf
Brush Script.ttf
DDT-bold.ttf
DDT-condensedsemibold.ttf
EngraversGothic-Regular.ttf
ForgottenFuturist.ttc
Franklin Gothic Demibold.ttf
GaramondRoughHEF-Medium.ttf
GaramondRoughHEF-Reg.ttf
GillSansUltraBold.ttf
Handwriting Dakota.ttf
HopperScript.ttf
Junegull.ttc
Loopiejuice-Regular.ttf
Luminari-Regular.ttf
OctinSpraypaint.ttc
OctinStencil.ttc
OldEnglishText-Regular.ttf
OperinaPro.ttf
Phosphate.ttc
Posterboard.ttf
SabonLTPro-Roman.ttf
Shababa.ttf
Shabash Pro Regular.ttf
Sinzano.ttc
SketchBlock-Light.ttf
Snell Roundhand.ttc
Soap.ttc
Trattatello.ttf
VIP.ttf
Virtus-Regular.otf
Wanted.ttc
Zingende Light.ttf
You can find these in Final Cut Pro (show package contents) / Contents / Frameworks / Flexo.framework / Versions / A / Resources / Fonts.
This is a different location than previous versions (Flexo.framework vs. TextFramework.framework). Option-click/drag the Font folder to your desktop (to create a *copy* of the fonts folder, then add the fonts you need via Font Book. I recommend creating an "FCPX Collection" to make these easy to find in Motion.
HTH