The search index should index all fields of all components, as well as text in binary files (PDF files, MS Word documents, etc.). I have an executable instance of SDL Tridion 2011 and can confirm that it really gives results from both binary and regular component content.
I'm not quite sure about the inner workings of the new version of SolR Tridion, but I think that the captions and the full text are indexed separately.
, , , , . " " ( "C:\Program Files (x86)\Tridion\bin\TcmPurgeQueue.exe" ) , . , , , , .
'*'. "Rampusplong" , "Rampusplong" "Rampus*" "*ampusplo*" , "Rampus" .