Joining lab groups

The first year students were allowed to officially join labs about a month ago. Technically we had until the end of October to join a lab, but everyone I talked to a month ago had settled on a lab by the earliest possible date (except for the people in the chemical biology program, who don't choose their labs until May). There are probably a few wrenches thrown into the lab joining process every year, and this year was no exception:

-One tenured professor is considering moving to another school, so people were kind of iffy about joining his group. I think two or three people ended up joining his group; I'm not sure if this is fewer than normal.
-One professor, Richmond Sarpong gave his tenure talk in September. He had an offer for a senior faculty position at another school, so his group would probably have moved there if he hadn't gotten tenure. Several first year students were interested in joining his group. I know one who said he came to Berkeley because he wanted to work in the Sarpong lab and thus was going to join the lab whether that meant staying at Berkeley or not. I think the rumor that he was awarded tenure was leaked right when people had to submit their group choices, and quite a few first year students joined his group.
-I heard about a couple of popular groups that did not have enough room for all of the students who wanted to join. In one case, there were eleven students who, a week or two before the deadline, expressed strong interest in a group that only ended up taking three of them.

My own lab-joining process was slightly stressful, but things worked out in the end. I had two potential groups in mind, but really wanted to join one over the other. I was worried for a while that I would not get into the one I wanted, but a combination of being a little pushy and other people losing interest seemed to push things in my favor. One good piece of advice I received was to be straightforward about what group I wanted to join, irrespective of what the group's situation was. That is, this person told me I should not allow my expressions of interest in a group to be tempered by how full/popular a group seemed to be, because if lots of students do that, then nowhere really ends up where they want to be. I knew this on some level, but I think it was good for me to have someone reiterate this.