Budding MCU engineer.

Dont worry whether the 8051 will die that fast. Just plunge into it, learn the architecture, mug up the instruction set and understand the timers and interrupts like the back of your hand. That way you will be able to take on any mighty processor as and when they evolve. I have seen many a student take so much time to analyse and learn the best and finally end up in some accounts or or personal department - nothing bad about the departments except they are non-tech.

And you said :
Some new laptop may even removed the com port.

Mine already has. Silly that way. I am using a RS232-USB adaptor and when I install the driver for that the WIN-XP warns saying the driver is not certified by MS and that everything will go up in smoke.( But nothing that way happened ) Gates wants HIS share in whatever YOU do.

Raghu