Why not have 1 btc as 0.00000001current btcs?
(or 0.000001btc, allowing for 1 btc to be split into 100..?)
It makes a 50btc block reward 5,000,000,000 btc (or 50,000,000.00btc) reward sound much better

This means if some addon/patch is done to create more divisible bitcoins we could then use the 0.xxxxxx?
2.1 x 10^15 doesn't actually sound like that many bitcoins if you compare it to USD M2 in pennies.
If such a change is made later it might be quite confusing, but as the user base isn't that large right now, why not plan something like this to hapen after a certain date so everyone is aware and is ready for it?
Some extra notes (13/may/11):
x | | Current Bitcoins | | | Bitcoins+8 (aka satoshis) | |
'Total BTC': | 21million | 21quadrillion |
Some examples assuming 6usd per btc and XE market rates...
100USD in BTC: | 16.66666667 | 1,666,666,667 |
1USD in BTC: | 0.16666667 | 16,666,667 |
1UScent in BTC: | 0.00166667 | 166,667 |
1EUR in BTC: | 0.23809524 | 23,809,524 |
1JPY in BTC: | 0.00206271 | 206,271 |
1KRW in BTC: | 0.00015319 | 15,319 |
1VND in BTC: | 0.00000817 | 817 |
Pronouncing values below 0 in the english language can get interesting...
a number like 1,543,234 can be read: one million five hundred fourty three thousand two hundred thirty four.
whilst a number like 0.1543234 is read: zero point one five four three two three four.
On the face of things current BTC looks shorter and easier, but it sounds very drone and as a listener it is very difficult to tell what value the number is.
(going to make a table of pros & cons here..)