Rihanna will release in September, it will be fairly successful but no Loud or anything. First single in June/July.
Taylor will release in November (

) and it will be a different and unique sound for her. More dark and moody. The GP will be mixed, but the critics will love it. Only the first two singles will be a massive success, the others will do well but nothing amazing. The album will also just barely open with 1 mil first week.
Gaga will release a few more singles but only one of them will reach the top ten, the others will underperform.
Katy will release a couple more singles but only one will reach the top spot.
Beyonce will see XO reach the top 5 and maybe #1. Otherwise the rest of her singles will be like previous eras. A couple top tens here and there and a couple flops. Overall she will have the second best selling album of 2014, after Taylor.
Adele will not release an album, but she will release a single. It won't slay as quickly as we all thought, but it will still do really well.