Some things... they don't transfer well.
Sorcerers... don't often claim to have descended from humanoids. Dragons, Outsiders, Fey, Other naturally super magical creatures, and the like. So... the spell-casting doesn't seem to fit.
"Hey how did you learn to manipulate the powers of space and time?"
"Uh... I'm a half-orc, duh."
Where are the Orc bloodlines derived from?
Feats, and powers?
They don't seem to be listed.
Orc-form is terrible.
Water-orc, Desert-orc, Half-orc... for a 7th level PrC ability, the options... don't do much of anything.
The straight transfer from Dragon to Orc doesn't seem to fly thematically nor mechanically. It looks like it wants more of its own things.