I find I don't care much about the bootloader LED blinking, as I bootload and then install Blink right off the bat to show the serial interface is working.
Excellent point. I can't recall even once checking for the bootloader to blink the LED.
Are there many serial things that run at 1 or 2M?
In my house there are.

The first thing I do when I get a new board is change the bootloader baud rate to 1 M. So all my Arduinos use 1 M baud.

The theoretical upload limit is essentially reached at 1 M. In other words, it's faster uploading at 1 M using a bootloader than using a dedicated ISP programmer.
Whenever I build applications that transfer data between a PC and an Arduinio I always use 1 M.
I could see that being handy for Arduino/Aruino comm's vs messing with I2C or SPI.
I've found the higher baud rate to be generally very handy.
Would be nice to not have to mess with adding 1284 variant back in every time an IDE is downloaded.
I don't think we will be able to get to that point. In the past, the Arduino policy has been to only include genuine Arduino products with the IDE.
I think we will be able to reduce the "core" to six files. The "core" will use the source code from the IDE (will always be up-to-date).