Ok, so it seems that for Western majority here the Eastern Europe has been defined during Cold War. (Eastern Bloc - essentially non Russian Warsaw Pact members)
My beef with it is that used nowadays it frequently is a vague reference to that past and conveys the ignorance about current state of affairs in Europe. It's became essentially meaningless now (it defines different area depending on who is defining it)
So is Poland in Eastern Europe geographically? Nope.
Geographical midpoint of Europe:
Slavic countries: Nope (Estonia, Latvia, Romania, Hungary anyone?)
Political divisions: Nope (see EU border, enlargement steps)
Does it include Russia? (it does for some: us.ishares.com/product_info/fund/overview/ESR.htm)
Just see Wikipedia article on Eastern Europe and check how many times political division between "East" and "West" shifted over current Polish territory.
Given all that confusion as a Pole I would prefer Poland to be referred as located in Central Europe.
It is a geographical term not burdened by all the political past and a nice starting point to further define what we are talking about.
I do not have much hope for that happening soon though :-)
It is funny to see sometimes the media being confused about it :
May 25 (Bloomberg) -- The euro has lost its allure for nations in central and Eastern Europe with floating currencies as their borrowing costs fell below those in some euro region states because of the Greek crisis, said ING Groep NV.
"central and Eastern Europe"? Why lo-cap, man?
Cyprus is a part of Eastern Europe acc. to Morgan Stanley :-)
"Poland is in Eastern Europe."
What do you mean?