Regarding when 2.51 comes out, the translation's a bit awkward, but so's the original Japanese. The original clearly says that 2.51 will come out between story part 1 and story part 2. The official translation just says that 2.51 will come out before you are bombarded with more content in part 2. But, there's no indication that they're talking about part 2 of the MSQ, not part 2 of the update series. The sentence rearrangement necessary for translating from JP to EN loses the context of what "part 2" refers to there. Regardless, referring to the third update as "part 2" is confusing in any language :P
Huh, the poem translation is interesting. Japanese is a pain to translate, isn't it? Comparing the official translation of the poem to my piecemeal translation of the Japanese version (using Google-Fu), it's interesting to see what I got wrong and why. "Now is the time to look to the past" (correct translation) in JP is very, very close to my mistranslation of "Aim now for the eye as in days of old." Basically, I mixed up "now, eye toward past" with "now, past, toward eye" and thought they were referencing the half-blinding of Nidhogg. Oops!
Also, I find it interesting that 鋭き槍 is translated as "Ivory Spear" - that's the kanji for "sharp" followed by ki (which I don't understand the meaning of in this context) followed by the kanji for "spear." I guessed the "ki" made it be "sharpest spear," but I dunno where they're getting ivory from? Definitely no color words in there. White is a strange color to use here anyway, since if they're referring to some famous spear of Ishgard, I'd expect blue (as in, azure) to have been a more appropriate random color to throw in given the EN version of the dragoon plotline.
And, what seemed to translate as "there are heaps of stuff so please enjoy it slowly" was actually "relax and enjoy the new content." Makes MUCH more sense like that :P
People have been referring to some kind of mystery trial in 2.5x - there's no mention of that in the patch announcement (original or trans), but there's also nothing at all about the zodiac weapon's final update either, so...