Battle.net now offers a list of hotfixes for Diablo III dated today (thanks Chris). The new server-side update addresses some bugs and increases the rate of high-end item drops for Acts III and IV in Hell difficulty and the entirety of Inferno difficulty. Here are the new approximate drop rates:

Items

• The drop rates for high-end items (items level 61-63) have been increased for Acts III and IV of Hell difficulty and Acts I – IV of Inferno difficulty:
  • The new approximate drop rates are as follows:
    • Hell – Act III and Act IV
      • iLvl 61: 9% to 13.9%
      • iLvl 62: 1.9% to 3.45%
      • iLvl 63: 0% (no change)
    • Inferno – Act I
      • iLvl 61: 17.7% to 23.9%
      • iLvl 62: 7.9% to 12.6%
      • iLvl 63: 2.0% to 4.8%
    • Inferno – Act II
      • iLvl 61: 18.6% to 23.3%
      • iLvl 62: 12.4% to 18.6%
      • iLvl 63: 4.1% to 9.3%
    • Inferno – Act III and Act IV
      • iLvl 61: 24.1% to 27.1%
      • iLvl 62: 16.1% to 21.7%
      • iLvl 63: 8.0% to 16.3%

Bosses

• Bosses are now guaranteed to drop at least 1 Rare item for players with 4 stacks of Nephalem Valor and at least 2 Rare items for players with 5 stacks of Nephalem Valor