Resistances can definitely help, which is why I was running Pokemon such as Scizor on my team, but I more heavily relied on Intimidate and bulk from Hitmontop and just the bulk of Mega Kangaskhan since my team was so offensively-oriented. You definitely do not need resistances to build a solid team, although they cannot hurt. Immunities and bulk are just easier to come by, as stated by youngjake, especially when top-tier threats such as Mega Kangaskhan are bulky and others such as Heatran have immunities.
On another note, I combination I have both played on the ladder and then subsequently tried out is SD Blaziken + Follow Me Jirachi. I still like Follow Me Jirachi in this metagame, even though it is obviously worse than in BW thanks to the Ghost- and Steel-type buffs. Regardless, I feel like this combination can set up on a wide variety of threats, although in my limited Doubles experience, I may be wrong. They are both beaten by EQ, obviously, but Blaziken resists Heat Wave, which is the most common Fire-type move in the metagame. Jirachi can also tank the priority moves aimed at Blaziken, and is bulky enough to survive many of the hits that would be aimed at Blaziken to knock it out, making this still a potent combination. Blaziken's attacking power and coverage means that, even without a Swords Dance, it can pose a threat to opposing teams. After a Swords Dance, however, it becomes very deadly, and the opposition will be forced to take it out quickly, which is exactly what Follow Me stops them from doing. This combination could work with Togekiss as well; Jirachi is just what I have played against and tested out myself for decent results. Follow Me support obviously helps a lot of Pokemon, but I feel that Blaziken is one of the best options to receive this support.
On another note, I combination I have both played on the ladder and then subsequently tried out is SD Blaziken + Follow Me Jirachi. I still like Follow Me Jirachi in this metagame, even though it is obviously worse than in BW thanks to the Ghost- and Steel-type buffs. Regardless, I feel like this combination can set up on a wide variety of threats, although in my limited Doubles experience, I may be wrong. They are both beaten by EQ, obviously, but Blaziken resists Heat Wave, which is the most common Fire-type move in the metagame. Jirachi can also tank the priority moves aimed at Blaziken, and is bulky enough to survive many of the hits that would be aimed at Blaziken to knock it out, making this still a potent combination. Blaziken's attacking power and coverage means that, even without a Swords Dance, it can pose a threat to opposing teams. After a Swords Dance, however, it becomes very deadly, and the opposition will be forced to take it out quickly, which is exactly what Follow Me stops them from doing. This combination could work with Togekiss as well; Jirachi is just what I have played against and tested out myself for decent results. Follow Me support obviously helps a lot of Pokemon, but I feel that Blaziken is one of the best options to receive this support.