Magicka classes have been able to use 2 handers for some time. Light / heavy attacks have been scaling with your highest stats for a while. This patch, weapon skills also scale with your highest stats. Whether you'd use 2H weapon skills on a magicka character is really only limited by your stamina sustain now. However, if you chose to run stamina weapons on both bars on a magicka character, your other problem is that you would have no way of restoring magicka from heavy attacks. I find this enough of a drawback that I would never do that. In other words: Always run a staff on one of your bars.

I don't see myself ever using a bow on a magicka character. Everything else is feasible. Dual-wield tends to give you marginally better stats than 2H, either by running 2 daggers in PvE for maximum crit or by running Nirnhoned + Sharpened maces for maximum pen and weapon / spell damage in PvP. This plays into templar's spell damage boosting passive and melee playstyle. It also gives maximum power to a nightblade proc build, e.g. Caluurion. 2H has some different advantages relating to kills and heavy attacks when you look over the passives of that skill line and it gives you Rally / Forward Momentum. One hand + shield has obvious defense potential in PvP, regardless of whether you play magicka or stamina. In practical terms, because you want a way to restore magicka, you tend to end up with dual-wield / resto (or ice staff) or with Destro / 1H+Shield in PvP. Of course 2H / staff can work as well, if you want to use 2H skills or passives.