Apple is sailing towards its fourth iPhone launch on the crest of a wave of market approval. Its iPad tablet has sold two million units in two months and is now going international, and it has overtaken Microsoft to become the largest US technology firm by market capitalization. Wall Street analysts are doing little to question the sad contrast. In near-simultaneous client notes, Bank of America Merrill Lynch raised its target for Apple, saying the iPhone was nowhere near saturation, while Barclays Capital cut its target for Microsoft, citing fears over the mobile software strategy. Does this really matter to the mobile world? Apple and Microsoft, outside the PC arena, have very different agendas and while their power bases overlap,…