First, a few quick observations:
l. 156: At puer Ascanius is also used at 1.267 (and I suspect elsewhere); it seems to be a formulaic phrase that fits smoothly at the beginning of a line.
l. 157-8: there is a nice parallelism between the separation of spumantem and aprum and that of fulvum and leonem; whether there is any particular purpose behind it, I am not sure.
l. 160: magno misceri murmure (the blog title!), as we discussed in class, is directly repeated from 1.124 and is very close to magno cum murmure montis from 1.55; clearly Vergil loves this particular bit of alliteration. At 1.124, it is used of the storm stirred up by Aeolus at Juno's request, suggesting that it is particularly a storm phrase. This may be a stretch, but it may be specific even to Juno's storms (i.e. ones unfavorable to the Trojans); the storm in book 5 that puts out the fire on the Trojan ships does not repeat the phrase. Another thought - is this magnus murmur foreshadowing the passage about Fama that is coming up - after all, what is Fama but a great murmuring/muttering?
The following lines contain more repeated phrases, in this case from Juno's speech telling Venus what she will do, only a few lines earlier (4.115-127). Commixta grandine nimbus changes only the case of nimbus, while the entire sentence Speluncam...deveniunt is repeated exactly. It seems to emphasize Juno's preparation, planning, and control (things happen literally exactly as she plans); I find this interesting because 1) Juno's beloved Dido is in the exact opposite frame of mind and 2) Juno's plans nevertheless fail completely.
The major issue of debate in the next several lines is how valid this "marriage" is; I am not going to go into a great deal of detail here, but some quick thoughts: 1) in the end, Vergil pretty clearly comes down against Dido in line 172 in particular - "she calls (vocat) it marriage, and she covers her fault (culpam) with this name." That seems to make it pretty clear that this is not a binding, official marriage. At the same time, one could argue that the setting - Mother Earth and Juno as witnesses, lightning for wedding torches, etc. - actually makes it more legitimate, rather than less legitimate as it is not exactly a public, official setting. On a side note, I believe ululo is commonly used of funereal mourning, which of course would foreshadow the disastrous result of the relationship, adding a subtle element to the plainer statement of 169-70.
Thoughts, questions, reactions?