2 dual purpose DSI/CSU connectors (you can now use two displays or two cameras instead of one of each)
A PCIE FPC ribbon connector like the one used for DSI/CSI (you don’t need a hat, just a ribbon) also the pi4 did not have any accessible PCIE lanes, only the cm4 did. Also the pi5 is capable of PCIE Gen3
More bandwidth for the usb3 connectors
more bandwidth for Wi-Fi (reports are it gets about double the bandwidth despite using the same Wi-Fi chip)
Fully SMD board, no through-hole components.
There’s plenty of stuff I would have liked to see that didn’t make it, but there definitely a lot more to it than an RTC and a power button. For $60 this is not a bad SBC at all.
I would have liked to see normal HDMI connectors, 2.5G Ethernet with PoE included, and higher RAM options.
More PCIe lanes would have been nice too but probably unlikely given the price point