Not ideal - this is a risotto rice. But you could use it and get an acceptable pud. It might be a bit more stodgy than using pudding rice because of the higher starch content, you could always use a bit more milk to counteract that.
i think it's delia smith who has an oven-baked risotto recipe, so i would imagine it's ok to use arboria rice to make a baked rice pudding. as has already been said, i would use more milk too. i do love a home made rice pudding, i think you've inspired me to do one too.