Two years ago, I think Unova was a lot simpler and more rural. Sky Arrow Bridge didn't exist, so people had to take a ferry. Route $ hadn't even been started, and few people lived or worked there, so to get from Castelia to Nimbasa, one had to chance a harsh desert. A person working in this harsh desert was an archeoligist named Lenora and her husband. They found the Dark/Light Stone and some new fossils (plume and cover, but they also had others) they had found, they set up an exhibit in Nacrene City. Lenora would battle trainers who came to look at their exhibit. Lenora soon was called by the Pokemon League asking if she wanted to be a gym leader. With the salary Lenora was making with her new job, they were able to open the museum(/gym)
Ghetsis had just begun to recruit members of team plasma, and putting his plan into motion. The seven sages were a cult-like group who Ghetsis commanded, and revered him almost like a high priest, and N as their rightful monarch. This helped to ensnare young ginger pokemon trainers into the ranks of team plasma. Alder had just lost his partner, and afterwards started to travel. Caitlin moved from the Sinnoh region to the Unova region to become a member of the Elite Four. Non Unova pokemon had began to appear at the edges of Unova, and some Unova pokemon like Audino, Emolga and Axew began to appear, but they were even rarer than they are already (shaking grass didn't appear very often) Also, deerling began to change with the season and a year or so later the Research Lab on route 6 would spring up. (haha season puns) A rich man found Victini, and wanting to protect it built Liberty Island.
The daycare on route 3 existed, but the preschool did not. Twist Mountain could not be passed through easily, as there was a lot of Debris from Clay's mining. So, Pokemon trainers would have to either climb over/around, but eventually a pilot from Mistralton began to fly trainers over the mountain once a week or so until the mountain was finally safe enough to travel through (about 6 months prior to BW) Iris began her training under Drayden and soon (within a year) rivaled his strength. In Undella town one of the Riches' cousins who lived in Lacunosa disappeared (he was eaten be Kyurem) and because the Riches' believed the legend, they all became pokemon trainers so as to be able to protect themselves. Also, the Abyssal ruins were discovered for the first time.
Well, that's all I got for right now! I'll add in later anymore of what I think Unova was like.