Just for the sake of the argument, would the war actually have gone on til '45 had jets been introduced successfully in '41?
Well, most of my readings usually states that the reason why Britain at times fielded rather, shall we say, not quite thought through equipment - mostly seen in their tanks - was down to wierd ideas about deployment and use (as with the tanks, the old cavalry idiots blunted Hobart & Co's attempt to build an effective mechanized army) and, not to forget, limited pre-war resources.
Fact was, as Redbeard often is fond of saying, and rightly so, Britain alone outproduced the Axis. Britain did not lack any weapons, but did lack an overall strategy and some sound ideas for use of their ground forces. Cancelling the Bomber Campaign will not change that.
That said, jets would no doubt wreck havoc on the bombers in 1941. Public opinion and morale would most likely - again it is ALL speculation, afterall it's AH - force Bomber Command to call off their attacks on Germany.
That would mean more focus on offensive weapons, less focus on defensive weapons. Fewer FlaK units, thus more guns, men and vital supplies for the Eastern Front. I really don't think anybody understand how much effort the Germans put intop defending their homeland from the Allied bomber campaign - just the strategic materials for munitions was a major resource drain. The numbers of guns deployed and the numbers of men to man said guns were very high. I seem to recall that at least 400,000 men served in the FlaK units.
Then there is the shift of fighters from the Eastern Front to the west, and deployment of night fighters, and the typical Hitlerisque idea of striking back, which meant that Luftwaffe was forced to conduct the small blitz, and so on... Perhaps even no need for the Germans to devout resources to the expensive V-programmes?!
Oh, and then we have the diplomatic implications. What will the British allies think, if Britain appeares to do nothing? The Soviets will be pissed off royally, and the Americans will most likely think theirs as well...
That said, in general I don't think it that unlikely to have seen jets appear much earlier. The technology was there and as long as we talk jets - not rocket planes -, it was not that demanding to put to use, and it had its proponents - Udet in Germany f.x.
Regards and all!
- B.