Excellent.
Is he alone? If so, you might want to look into eventually getting him some sort of companion. It is true that humans become part of their herd, but horses also appreciate nonhuman company -- you obviously can't be out in the pasture with him 24/7. My gelding was isolated for two years at his last home and it near drove him insane...he had wore a trench in his corral with all the frantic nonstop pacing. Now surrounded with other horses, he hasn't paced once.
As far as your new boy goes...don't tolerate any mouthy behaviour, no matter how cute. It can escalate into nipping. Pushiness and invading your space as well are big no-no's. Get to know him, brush him, sit out there quietly with him or sing softly...but it's important that he sees you two as his strong and confident herd leaders. In a little while once he's feeling better, there's a strong possibility he'll begin testing you to see you are "worthy" of being the alpha mare. Just be prepared and remember to be firm. Don't worry about hurting his feelings.
In the pasture, you'll notice other horses respect the personal space of the alpha horse. If he ends up barging into you on a consistent basis, it is a sign of disrespect and can escalate into dangerous behaviour.
Also be aware that some horses can develop biting if they are hand-fed treats.
Don't mean to be the harbinger of doom here, just giving you a head's up. It could be he'll be a perfect gentleman with no issues, but you guys have a lot of getting to know-ing to do! I've been through the wringer with my gelding as he was allowed to just walk all over his previous owner, and he's a big and intimidating boy, lol. But we're getting things ironed out. There's always a light at the end of the tunnel, as they say.