As our numbers become more solid, 538 has a good breakdown of how the swing (and other competative) states performed in 2020 versus 2016 (and earlier trends.)
Some key takeaways.
The "Blue Wall" (Wisconsin, Michigan, and Penn) states have been moving into the Red for several election cycles now, peaking in 2008 to Trump narrowly taking all 3 of them only for them to narrowly swing back to blue for Biden. Time will tell if this is a trend or an anomaly. I'm also wondering if all 3 states will stay so consistent in how much they mirror each other.
Arizona and Georgia voted blue for the first time decades. Both states have been moving more blue since 2008. Georgia might have been due to the impact COVID is having there an Arizona might be a case of "Hey maybe openly taunting and insulting the dead hero of a state I needed to win wasn't the best idea" but both states seem to be moving in a more blue direction even before either of those factors.
North Carolina and Texas both continue to move toward the blue side, although both went red this election. Texas turning blue is one of those Holy Grails of Democrat politics for obvious reasons. Both the symbolic nature and EC count nature of such a win would be enormous.
Florida (possibly the only state where Trump did meaningfully better than in 2016) seem to be moving more toward the Red. Florida is such an odd duck to try and "moneyball" politically because basically unlike the "educated urban versus uneducated rural" divide that makes most other "Red States" or "Blue States" red or blue, Florida is waves of old retirees filling out retirement communities across the states versus waves of Latin American Immigrants making up a significant chunk of their big cities. I'm guessing that Florida doesn't have as many "White Liberal" strongholds as other states and from what I'm hearing the Cuban and other immigrants in the traditionally blue strongholds of Miami and surrounding areas
Colorado and Virginia might be safe blue states at this point, as well as Maine, Minnesota, and New Hampshire.
Ironically the two perennial swing states; Ohio and Iowa, barely moved their needles at all.