Wow! I'm seriously looking forward to this! Ami looks terrific!! And look at the dejected look on Moon's face! I'm so impressed with Sawai Miyuu. Her acting has really come along!
I think putting Moon's attention back on her friends is crucial at this point in the series. Ami turing evil will be what brings them all together, IMHO. They've been keeping secrets, working separately, bickering, etc etc, so I think this will be the turning point.
This would also be a great moment for Venus to join the team, if she ever plans on doing so. As she's currently bed-ridden, she'll have to work with them. Or at least Artemis will have to seek them out, since Minako is too sick.
Since the attention is away from Tuxedo, this is also the perfect time for him to get together with Hina and break off the relationship. Once the whole thing with Ami dies down, he'll be right there for Usagi. xD
Where the princess things fits in... I don't know. This could draw out the series to 52, right? What do y'all think?