After the $1K mark today; I've been -literally- bombarded with questions about the "roof" the price will be "landed". I know that bitcoin is nothing like anything we know up until today; but still; we can estimate a projected value regarding something similar. Gold.

This is a rough estimation I did back in March (before the April crash). I think it remains pretty accurate to give you an idea. It's also posted at www.bitcoinvest.eu for Greek readers.
The money in circulation today ($USA) is 1,18 trillion dolars (data 20.03.2013, Federal Reserve). Gold minted during our presence here is now 171,300 metric tons. Therefore there's $6,888.5 per kilo of gold. The current (27.03.2013) gold value per kilo is $51,267 (http://goldprice.org/) which means this is overpriced about a factor of circa 7.5. That's because NOT ALL of gold is available for trading.
If the total lot of bitcoins reaches 21M (it comes @ 2140) and NO EXTRA DOLARS are being "cut" (unlikely, but say it is so), the projected theoretical value is 1,18 trillions of $ /21 Million Bitcoins= $56,190.47 per bitcoin.
If you now take in mind the overpriced hypothesis of gold; then you get the idea...

PS:
It's also posted here answering (guess) the same question...  
http://np.reddit.com/r/Bitcoin/comments/1rloww/serious_question_do_we_have_any_reasonable_idea/

If you have any objections; please let me know.