NO WAY :

I was able to upload the blink sketch to the lilypad.
Then I modified the pin value in the blink sketch, recompiled, and attempted upload with lilypad selected.
The result was the sync error. Thinking I needed to upload to the diecimila I disconnected the lilypad, reset the diecimila and uploaded to it without issue.
Then I reconnected the lilypad, selected lilypad from the IDE, reset the lilypad and attempted upload again.
The upload to the lilypad failed and now the led no longer blinks from the blink sketch. It's like the lilypad lost the blink sketch and was replaced with nothing and i can't upload anything now. I know this sounds crazy. Note that my lilypad does not appear fried cause the led still blinks regularly with the tx/rx connected to the arduino.
Arrrrrrrrrgh !!
Pirate arrrgh.
With the diecimila I have changed pins, powered LED's, etc, etc all within 30 minutes of receiving it.
The lilypad has been nothing but PAIN.
Leah - respectfully, can i send you my lilypad to check it out? this can't be just me...the deicimila is like a parkwalk to me so i'm fairly sure i'm not a total idiot :-/