i think it might be susan because why would they show carl? and also if it was katherine wouldn't susan be there, she would be happy for mike! and.. mike has loved susan this whole time.. it's so obvious he always wanted to be with her! but it could be katherine, they could shock us and make it look like he's marrying susan but when they lift up the vowl it'll be katherine! but i'm not too sure, i i hope it is susan (yn) it is really killing me not kknowing! oh and also the hair looked brown if you ask me!