One of the major progressive steps in the Renaissance in terms of literature was the increased use of the vernacular.  As more copies of the Bible were being translated into the vernacular language of the region, this appraoch became more accepted and even preferred.  Literacy increases, and then of course with the invention of the printing press, the use of vernacular language became mainstream.

It is true that the Renaissance was a renewal of a Classical model insofar as interest changed from a localized perspective to a perspective that expanded to embrace a unified model of Classical values, aesthetic and knowledge. This began with literary interest as Classical writers were rediscovered by scholars like the poet Petrarch.

 http://www.artchive.com/artchive/renaissance.html

The divide between the wealthy bourgeoisie and the poor proletariat continued as well. Many artists were wealthy and could spend hours and hours perfecting their art, while farmers and servants toiled to allow them their comforts. In this sense, the fiefdoms and serfdoms of prior years continued, albeit at a smaller level. Time is essential to invention, even more so than necessity, to work out small details.

Renaissance means, "to be reborn," and that "rebirth" has happened again and again throughout the history of this planet.  Anytime there is new technology, new ideologies, and new thinking, there is going to be a general change in the way things are done, looked at, and thought about.  It didn't just happen after the Middle Ages, but several times after that.  For instance:  the Revivalist and Impressionist Movements of the late 1700's and 1800's showcasing both religious and cultural shifts; the Industrial Revolution affecting all aspects of people's lives, even spilling over into drama, poetry, and music; and more recently--the Technological Revolution in which electronics, music, and art have exploded into areas and forms the likes of which have never been seen before! 

Medievalists (I work with one) hate the idea that the Middle Ages were simply an era of barbarism, and even most modern Renaissance scholars tend to question the assumption by Renaissance-era thinkers that they recovered classical wisdom and thought after a long period of darkness. Intellectual historians have pointed to late medieval Thomism and Aristotleian thought in Spain and in the universities of Northern Italy as examples of continuties. Also, some scholars have noted that concepts of critical inquiry did not emerge without precedent during the Renaissance: William of Ockham, Averroes, and Roger Bacon are cited as distinctily modern philosophers from the Middle Ages. These historians do not dispute that major changes took place among European intellectuals during the Renaissance, but argue that these changes represented a continuity with, rather than a total break from, medieval thought and culture. I have attached a link below that deals with some of these continuities. You might want to look at the work of George Sarton, James Franklin, and Robert Spasnau for more in depth examples of this line of argument.

http://www.unisi.it/ricerca/prog/fil-med-online/manuale_eng/modernita/htm/home_modernita.htm