Well, if he would've died or been killed or something before the start of WW2, then MAYBE he would've been hailed as a hero - but in Germany only. In the other countries, there's a possibility that they wouldn't say negative things about him, but that they wouldn't really accentuate the positive either.
Why would he be hailed as a hero by Germans? Why is it even POSSIBLE?
Well, after Versailles, Germany was completely humiliated and the treaty may or may not have been too harsh (maybe it was in fact too lenient? i mean there were plans to completely divide Germany into several separate states), but the German people were certainly humiliated and it fueled their hatred and lust for revenge. This hatred, in turn, gave the nationalists, extreme-rightwingers (such as the German Worker's Party, which owuld turn into the National Socialist German Worker's Party), monarchists, and counterrevolutionaries the support they needed. The German Revolution of 1918 was actually "aborted". It didn't really go all the way - social and land reform was not completed. The entire country was in virtual anarchy from late 1918 to 1919, and even into 1920. The SDP barely was able to hold power - the Bavarian secession was the result of an Independent Socialist Party-led revolution, resulting in a radicalized socialist republic in Munich until the Freikorps, veterans and right-wingers organized into paramilitary, entered the "republic" and crushed the gov't there. Then, in 1920, even they revolted against the Weimar Republic because it was still very weak. While democracy endured on shaky foundations until the 1930s, nationalists were gaining power. THere was a major fear of communists and hyperinflation ravaged the nation. In Austria, one of the main reasons for the popular resentment as because Anschluss, or union, with Germany was strictly forbidden. Both countries were basically destroyed and were no loner respected. The people became disillusioned with the Weimar democracy because the nationalists and other anti-democratic right-wingers scapegoated the Weimar-Republicans as traitors and the real reason for Germany's defeat in WW1. While in the latter half of the 20s, Germany was making a stunning recovery, it was still pretty weak because the Reichstag had proportional representation system - even the tiniest parties could get in if they had any votes, fracturing the Reichstag and forcing the moderates into coalitions. And, like I said, Weimar Germany was making a recovery in the later 20s, but then thje Great Depression happened, hyperinflation returned, and unemplyment soared again. This pushed the gov't to the edge - it resolved to using the Emergency Decree law of Article 48 to maintain power as the Reichstag was blocking a lot of the laws that the executive branch proposed. This turned pre-Nazi Germany from democratic into authoritarian and almost allt he time until its complete collapse, the Weimar Republic used the Article 48 to keep power. By 1932, the coutnry was on the brink of civil war - the nationalist extreme-right vs. the communist extreme-left. The President appointed Hitler as Chancellor because he thought he could be contained that way. He was wrong. Hitler gained full power because the Reichstag was by then almost completely Nazi-controlled and issued the Enabling Act. THe Great Depression almost destroyed the "reforms" that the Weimar Republic had brought in the later half of the 20s, so Germany's infrastructure had to be rebuilt again. Hitler did that, even though he crushed any and all opposition and used extreme racism and nationalist propaganda to "hypnotize" the masses into supporting him. So chances are he would be called a great leader by Germans had he keeled over in 1938. Then, after his death, there would probably be a power struggle because even when he was alive the higher-status gov't and military people bickered among each other and coveted the powers of the office of the Fuhrer. I wouldn't be surprised if, had he died in 1938, Germany would disintegrate into civil war.
No, I am not pro-Nazi, I am not pro-Hitler. I hate both very VERY VERY much. But we can't deny facts - and the facts were that Hitler did temporarily improve the majority of German (well, at least ETHNIC German) life. So it is a big possibility that ethnic Germans (German-Germans, Austrian Germans, and Sudeten Germans) would praise him.