What contemporary criticism was given to Belloc's claim that the Protestant Reformation was the work of a few oligarchs? I've just returned from the 33rd Conference of the American Chesterton Society with exciting news,  apparently Protestantism is a sham inflicted upon us by the corporate elite! 

Hehehe, well who knows... But I've been on this site as long as anyone and I found it very surprising to hear Hilare Belloc's thesis on the over-arching cause of the reformation.  I knew from reading the Servile State that after the Reformation it was apparent that the lords looted the monasteries.  


  "What! this large national movement to be
  interpreted as the work of such minorities? A few thousand squires and
  merchants backing a few more thousand enthusiasts, changed utterly the mass
  of England?" Yes; to interpret it otherwise is to read history backwards.
  It is to think that England then was what England later became. There
  is no more fatal fault in the reading of history, nor any illusion to
  which the human mind is more prone. To read the remote past in the light
  of the recent past; to think the process of the one towards the other
  "inevitable;" to regard the whole matter as a slow inexorable process,
  independent of the human will, still suits the materialist pantheism of our
  time. There is an inherent tendency in all men to this fallacy of reading
  themselves into the past, and of thinking their own mood a consummation
  at once excellent and necessary: and most men who write of these things
  imagine a vaguely Protestant Tudor England growing consciously Protestant
  in the England of the Stuarts.
  
  Hilaire Belloc - Europe and the Faith


But, does anyone have any evidence against the notion that it was what would become the aristocracy who started the reformation in Britain?  Did people take Belloc seriously.  I've read recently that he's been found correct time and time again, but always seen as a heavy handed Catholic reactionary in his day (which makes him quite a hero to me) who no one took seriously because he wrote in a vulgar manner and not only for scholars.
What a fascinating question -

Was the Protestant Reformation a bottom-up or top-down reformation?


It would seem the only reasonable answer is - Yes! (i.e. both)

The progress of the Reformation in Scotland showed all the hallmarks of the former - cf. http://en.wikipedia.org/wiki/John_knox :


  John Knox (c. 1514 – 24 November 1572) was a Scottish clergyman, writer and a leader of the Protestant Reformation...


While it's genesis in England showed distinct signs of the latter - cf. http://en.wikipedia.org/wiki/Henry_viii#Reformation :


  Henry is generally credited with initiating the English Reformation – the process of transforming England from a Catholic country to a Protestant one...


Of course, the crux of the matter is - what was the situation in Continental Europe and in particular, what were the circumstances surrounding Martin Luther and the very beginning of the Reformation?  Was Protestantism really birthed out of the objections a Theology professor had to the 'Indulgance Industry', or were there dark forces at work behind the scenes - worldly potentates plotting to appropriate ecclesiastical booty for their own aggrandizement - pulling Luther's strings?  Well according to most accounts (at least the ones that don't have a specific axe to grind), the evidence points very much to the former (cf The Economist's article How Luther went viral).  While the nascent Reformation did catch the eye of at least some Princes relatively early on, it wasn't until some years later that this translated into official breaks with recognized Church (and in the case of the member states of the Holy Roman Empire, temporal) authority which admittedly bore some prospect of enrichment at the expense of the church, but also the high likelihood of war with states loyal to Rome - it was no light undertaking, and it least in the case of the German states, was far more likely to be the result of conviction than opportunism. (cf. source 1,source 2 &amp; source 3)

Is there more evidence that there was actually something in Reformed 
Christianity that appealed to the peasant?


Absolutely: The Reformation all started with preaching against (purchaseable) indulgances - which amounted to enabling the rich to buy their way out of purgatory. Of course to the extant that a peasant was aware of the practice, he was aware of an injustice - perceiving the church favoring the rich;  In contrast the doctrine of salvation by grace alone through faith alone - the free gift of God through Christ - would have been the very breath of heaven on his soul.  Although Luther himself criticized what he saw as the excesses of the Peasant's rights movement that lead to the German Peasant's war, and there were many factors that precipitated that conflict, adoption of Protestant doctrines (especially those that pertain to choosing revealed truth ahead of obedience to earthly authority) were a definite part of the mix.

Summary: Although there was a measure of top-down influence on the development of the Reformation (especially in England), the dominant characteristic was actually bottom-up and Belloc's thesis is not well supported by a comprehensive overview of the genesis of Protestantism.