Yes, in Arduino (1.0), I have made an entry in boards.txt that looks like this:
usbtiny128.name=[usbtinyisp] ATmega128v@ 16 MHz
usbtiny128.upload.using=usbtinyisp
usbtiny128.upload.maximum_size=129024
usbtiny128.build.mcu=atmega128
usbtiny128.build.f_cpu=16000000L
usbtiny128.build.core=arduino
Then I select Tools->Programmers->USBtinyISP and I can load a sketch directly to the board through the ISP header.
In wiring, I tried a couple variants of this in the boards.text file with no success. For example:
usbtiny128.name=[usbtinyisp] ATmega128v@ 16 MHz
usbtiny128.upload.using=usbtinyisp
usbtiny128.upload.maximum_size=129024
usbtiny128.build.mcu=atmega128
usbtiny128.build.f_cpu=16000000L
usbtiny128.build.core=arduino
This shows up as a board, but when I try to upload a sketch I get this error message which seems to indicate that it's still trying to upload via a non existent bootloader:
java.lang.NumberFormatException: null
at java.lang.Integer.parseInt(Integer.java:417)
at java.lang.Integer.parseInt(Integer.java:499)
at processing.app.debug.AvrdudeUploader.uploadViaBootloader(AvrdudeUploader.java:85)
at processing.app.debug.AvrdudeUploader.uploadUsingPreferences(AvrdudeUploader.java:55)
at processing.app.Sketch.upload(Sketch.java:1611)
at processing.app.Sketch.exportApplet(Sketch.java:1666)
at processing.app.Sketch.exportApplet(Sketch.java:1621)
at processing.app.Editor$DefaultExportHandler.run(Editor.java:2476)
at java.lang.Thread.run(Thread.java:680)