If you have 10+ spades in your hand, you will never let a contract die out in 3S now, would you?

It really depends on the hand, but people play the following two conventions which might potentially be useful (of course, there might be others).


Namyats. This is to distinguish hands which are too strong for just preempting 4S. You show stronger hands by bidding 4D (taking spades as your suit), which you could potentially use here, though 10+ would probably be too strong. There are various followups which can be used to investigate slam.
4NT opening bid as Ace asking. Say you had AKQJxxxxxx, A,x,x. You could bid 4NT as asking for Aces, and bid the slam appropriately.


Anyway, hands with a 10+ suit are very rare and even experts have trouble with them (or rather, don't bother with them so much, because of the rarity).

As to your question about opponents taking out to their suit, why do you think that is likely to happen? It is quite risky for them to be bidding at the 5/6/7 level, without a running suit of their own. Your bidding at the 4/5/6/7 level would have taken out enough bidding space to make it unlikely they would be able to overcall easily (and find a fit). You seem to be also forgetting that you have a partner who could still hold some cards, and could easily double them and take them for a number. If they do bid, well, you can't help it, but I would say it is not as likely as you seem to think.



As to your edit.

Yes, any specific hand (down to the spots) is a low occurrence (in fact same chance for each hand!), but bidding systems are not geared towards finding the exact specific hand you have. Bidding systems are geared towards finding fits, distribution and strength with the ultimate goal of finding the right strain and level based on the scoring.

When talking about 'rarity', you should be thinking in terms of hand types rather than specific hands. So when someone says getting a 7 card spade suit is much more likely than getting a 10 card spade suit, they are not talking specific hands, but a set of hands. Take the set of all hands which have 7 card spade suit and the set of all hands which have a 10 card spade suit and compare the counts. 

When people say 10+ card suits are rare, they are talking about the whole set. 

You might never get the same hand dealt again, true, but the same hand type (say 15-17 balanced) might occur again frequently.

Bidding space is very limited, and trying to cater to rare hands can be inefficient use of that space.

How should hands that are EXTREMELY strong in one suit (10+ cards) be bid?
Is it possible to be able to set some default settings, such as the display format of dates of posts? (For example, I would much rather see 2011-13-01 than the current jan 13 '11)

In addition to an alternative datetime format one could also think of some other settings, perhaps some color blind settings, light/dark-theme or some other stuff I'm sure some clever people here can think of.
