Actually the permanent residents of Outreimer, by this I mean crusaders who stayed in the holy land and their decedents, were rather pragmatic. Once the religious high of completing your oath was over, the crusaders had to deal with realities of ruling a foreign population, potential enemies on most sides, their backs to the sea, and possible aid months or years away. Later crusaders had quite the culture shock when they went over to Outreimer. Of course, there is the fact that most crusaders went back home after reaching Jerusalem which left the kingdom in desperate need of soldiers and thus the continuing crusades being called. Early political instablity among the crusader states also caused problems.
Now, to get the language lets consider the following scenario. Suppose Urban changes the call slightly in that the crusaders are to free and insure the continual defense of Jerusalem. This way, crusaders have to stay in the kingdom. Naturally, this will change who is going and they're probably going to bring they're families with them. Now assuming that everything plays out roughly historically, we can end with the post first crusader states having 20,000 fighting men and their families. I chose this number based on the peasant's crusade, the noble crusade, and the crusade of 1101 (when the people who had made the crusading pledge but had not gone earlier went on crusade). This should give the states enough manpower to defend themselves considering the state of the region baring a major military disaster. Given where the preaching for the crusade was directed in OTL, we can assume that the most of these settlers will be speaking old french and the Italian dialect popular in Sicily.
Given the seinario outlined above, I think Outreimer's language will follow a similar path as English did. By this I mean that the native Arabic will be altered by the influx of French and Italian until it is transformed into a new language.