Has this been done/or even possible?
And if so can I have the links explaining how, who, what, and when please ;D
Other AVRs?
What "other" AVRs are you speaking of?
Something like this?
http://www.pjrc.com/teensy/
Sure it's possible.. is it really that hard to search?
Other AVRs?
Yes other AVRs, or do Atmel only make the ATmega8, ATmega168 and ATmega328 
What "other" AVRs are you speaking of?
Oh I don't know, maybe some of the The Atmel ATtinys like the 2313 that are used well know Ladayada projects.....
Something like this?
Teensy USB Development Board
Thanks for the link, that useful in regards it shows it can be done.....how is another matter though.
Sure it's possible.. is it really that hard to search?
Yes it is, when you don't know what your looking for.....have you seen the goggle results for "other AVRs arduino IDE" I personally didn't find it that enlightening.....how about you point me in the right direction.
Beside ATmega8, ATmega168 and ATmega328 you cited, ATmega1280 (in Arduino Mega) and ATmega644 (in sanguino and in Duino644) are also covered by Arduino IDE.
As for ATtinys, there wouldn't be much space for a bootloader (which takes about 2KB), since their flash memory is only 2KB.
there are, in fact, arduino cores for attiny2313 and attiny84. do a search on those terms and you should turn them up. As noted, there's no bootloader for either one as far as i know.
PIC versions:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1262278232/all
See this post for more on ARM 'arduino':
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1227128468/0
Mowcius