No.
You can run flashme on it, or one of the few other firmwares available (not that I would suggest anything other than flashme). No ability to meaningfully upgrade through the stock firmwares.
Why would you want to anyway? The only thing I can think is you might have read about the higher firmware devices supporting the DS lite style brightness adjustments, however that was not the fault of the firmware but the hardware they came with -- your early model DS lacks the chip that controls the brightness in that way.