There is no change in the Acrobat 11 EULA with respect to the limit on submtting Reader Extended forms.
You can find the Acrobat 11 EULA here - http://www.adobe.com/products/eulas/pdfs/Gen_WWCombined-comb-20120712_1830.pdf
Section 16.8.3 is the relevant section. Essentially you cannot extract information from more that 500 copies of a form OR distribute a form to more than 500 recipients (without limits on the number of times you can extracti data from forms submitted by those reciepents).
What about if you have purchased a FormsCentral account that allows unlimited forms, instances, and responses? Doesn't that make a difference? And does that apply only to Acrobat forms or to LiveCycle forms as well?
In the case of FormsCentral, while the PDF forms that are used with it are indeed Reader-extended, they are Reader-extended by the FormsCentral server, not Acrobat, so the Acrobat License Agreement doesn't apply.
The contract reads:
"For the avoidance of doubt, if Customer purchases another Adobe product or service that allows Customer to send a greater number of PDF files or forms (e.g., Adobe FormsCentral or Adobe LiveCycle Reader Extensions), then the terms of that Adobe product or service shall supersede the terms of this Section 16.8.3."
The 5000 response limit is specifically how many responses are allowed in the responses table at any one time. There is a 2500 response buffer so you don't lose any, so you can simply remove responses from the table to restore any in the buffer and allow more responses. Export the data before deleting responses so none are lost.