That being said, I have made millions of credits by crafting level 49 blue quality armoring, mods, and augments. These entry level end-game items do not sell for a lot individually but they do sell consistently and persistently over time.
And I guarantee that when the level cap raises, whatever the level 54 stuff works out to be will sell just as well. Why? Because they are typically reasonably priced for what they offer - when an Advanced (purple) augment runs 50k+ and the blue augment runs for at most 15k (more commonly 10-11K) and you only forgo two points in each stat a given augment provides spending a LOT less for a little less is a great option. Min/maxers and hardcore raiders will disagree but that is a different argument.
The point is that crafting is not worthless and never will be worthless so long as their are players like me who craft for those not wholly interested in the top top top end, and there are buyers who are OK with equipment not necessarily being top top top end.
I would add that level 49 blue mods, armoring, etc. is a good way to strengthen companions when you first hit cap. I don't believe that there will be free gear when you hit 55 and if that is so, there should be more demand for the level 54 crafted stuff then there is for the current level 49. I would expect that the level 51 to 54 stuff will be expensive at first since it will take time for the more casual crafters to catch up and hence the supply will be low.
One key is the fact that most player are not raiders and they will have a need for the higher level stuff. I am not sure how the new commendation caps will work out, they may also decrease availability of mods, etc. I expect the 51 to 54 market will be strong at first as a large number of people get back into leveling again to bring their 50s to 55 (depends on he drops and commendation returns).