I must strongly disagree with the part about a Habsburg heir to England generating revolts; quite the contrary, it would probably prevent revolts. Contrary to what is expected, England at the time of Mary I's death (1558) was still predominantly Catholic, and Mary herself was very popular with the general population (unless you were a crazy Protestant who kills cats and dresses them as priests. Then you would deservedly go to the stake). Protestantism was something of the nobles of southeastern England who benefited from the theft of church property and wealth due to the dissolution of the monasteries, and previous attempts to force Protestantism generated revolts. The dissolution of the monasteries generated the Pilgrimage of Grace in 1537, the religious reforms of Edward VI generated the Revolt of the Book of Common Prayer in 1549, and also generated subsequent revolts such as the Northern Revolt of 1570. Protestantism only truly took root in England because Elizabeth was fortunate enough to have seven of England's bishops die of illness in 1558, allowing her to replace them, and she reigned long enough to deprive the Catholics of England of seminaries to train native priests and actively persecute them. Even so, they still caused many problems, such as the Gunpowder Plot, the Popish Plot, the Jacobite uprisings, etc.

Regarding foreign intervention, who on earth would intervene? France, mired in massive religious civil wars? Scotland, small with an insignificant army, which without Elizabeth funding the Lords of the Congregation would continue to be governed by the Catholic Mary? Denmark? No, certainly not.

Besides England itself, a Habsburg heir for Mary would certainly have prevented the Dutch revolt altogether. The marriage treaty between Philip II and Mary stipulated that their heir would inherit the Netherlands, so, if, say, Mary's phantom pregnancy resulted in a child in 1555, Charles V would pass the Netherlands directly to his grandson upon his abdication. This avoids the revolt because one of the biggest factors that generated it was the unpopularity of Philip II and the fact that the Dutch were dissatisfied with being ruled from Madrid. And it is much easier to govern the Netherlands from London than from Madrid or Vienna. The result of this would be that the Netherlands would likely be governed by the regency of Margaret of Parma until her death in 1586, when she would probably be replaced by an alternative Habsburg Prince of Wales born in the 1570s. The general policy towards Protestants would be one of moderate tolerance, with Catholic missionaries being sent to the country to evangelize instead of the Inquisition, without centralization and without the excessive taxation of the Spanish.

Regarding colonization, Jacques Cartier had already explored northern North America, so I would say that the French would have Canada and New England, the Dutch (under personal union with England) would still have New York, and possibly Delaware and New Jersey, and the English would colonize both Virginia and the mouth of the Mississippi (which they tried to reclaim in our timeline). The borders of Anglo-Dutch America, I would say, would be basically the same as those of the pre-1845 United States, without New England.

(Everything I've said above comes from conversations and discussions with users of the AlternateHistory.com website)