Towards understanding "extraterrestrial" life - and intelligence? At least we should expect the observation of a "population" of earth size and even smaller objects, and perhaps be able to say something about what "typical planet systems" and "typical conditions" are like?
And perhaps gain some information about surface conditions, different stages in development etcetera. Is it not so, that the search for extrasolar planets and for organic chemistry in space untill now have been the two succesfull paths towards understasnding life in other places, compared with other ways?

Within the next 10 years we'll have started collecting a brochure of earth-sized planets, don't know if we'll know much about their atmosphere of stuff like that.

Perhaps the systematic study as suggested by the OP adds the much needed knowledge to initiate the "catalog" of "typical earth-sized" planets--but as for the chemistry and possible life(?) --- will you please expand upon your statement:

And perhaps gain some information about surface conditions, different stages in development etcetera. Is it not so, that the search for extrasolar planets and for organic chemistry in space untill now have been the two succesfull paths towards understasnding life in other places, compared with other ways?

(my bold emphasis and underlining)

In short: what are the two successful paths and what are your comparisons?

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"The candle flame gutters. Its little pool of light trembles. Darkness gathers. The demons begin to stir."
---Carl Sagan

Re jhwegener:
My op is generally conservative; while I think that we'll have great data on planetary distributions (in terms of mass, primaries, and metallicity) by 2020, quality spectral data (for close-in, Earthlike planets) will have to wait for next-generation instruments which are IMO, over the horizon.

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"Call me old-fashioned, but I think fire is magic. And it scares me a lot."

--The State

I could not agree any more with you-- but my question was directed toward jhwegener -- and what he meant in the details of the post?

__________________
"The candle flame gutters. Its little pool of light trembles. Darkness gathers. The demons begin to stir."
---Carl Sagan

In the next 5 years, the Kepler mission will give us an idea (basee on a statistically significant survey of 100k stars) of how many planetary systems there are in the galaxy, as well as mass, composition, period, etc. It will be looking specifically for earthlike planets in the HZ of sunlike stars. Most of these planets will be far away, ie > 200 LY.

in 2012(ish), Kepler's next evolution , SIM (?) will be able to scan the entire sky in 7 years and identify any stars within 30-60 LY that host earthlike planets. That gets us to 2020 with good data on planetary systems.

By the time SIM is in full swing, we will have all the data analyzed by kepler, and could be doing spectronomy on identified terrerstrial type planets to determine atmospheric composition, with the possibility to identify worlds where there is earthlike life - if it exists. See this thread.

Therefore, in the next 10 years, I expect we will have answered or approximated these questions:

1. Percentage of sunlike stars that host planetary systems
2. percentage of stars with systems like Sol's, with gas giants and inner rocky planets (which to many scientists is a requirement for life)
3. How accurate are our current models for 'typical' planetary system formation.
4. How ubiquitous are earthlike planets around these stars where liquid water can exist on the surface.
5. Beginning to analyze and characterize the atmospheres on rocky planets using spectroscopy, with a chance of finding a few candidates where life processes may be occurring.

I do wish that would be the case, hwegener,... but somehow Im not optimistic. The way its going right now... moon mission being scrapped and all... it seems that we are stuck on this planet.

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I still await the compelling Exhibit A.

The two succesfull paths 1: Observing organic molecules in interstellar space. 2:Observing extrasolar planets.

Compare to: Untill this day no evidence of extraterrestrial life wherever it may exist.
No signal or sign of intelligent aliens.