The right was is to flash the matching recovery and use the pkg, assuming you're not on honeystreak.
Tegra2 device users are far too reliant on nvflash to do the work for them.
I think that's good advice, provided you're not rooted with CWM. Unfortunately, I was and the update.pkg would not work (of course, because CWM took its place).
If you're rooted, you should do a full Dell wipe/restore, which I believe unroots and clears CWM. I haven't tested this yet though.
In frustration last night I flashed Honeystreak to my T-Mo DS7, after failing to flash the new (HC) US WiFi .pkg - wish I was thinking more clearly then.
So, my plan is to:
[*] nvflash the 2.2.2 ROM floating on this forum. (hoping that I don't get the read-only result)
[*] If that rom is rooted, I'll flash CWM. If not, I'll root first.
[*] I'll flash the nandroid recovery I made before all this business happened and back up a few odds and ends I missed.
[*] Flash the stock recovery through security settings
[*] Flash the US WiFi .pkg as update.pkg
And pray. I like Honeystreak so far, but the Asus branding throughout the ROM annoys me, and I do not mind Dell Stage as much as other here do. Hopefully the 4G driver will continue to work, but I do not use the 4G anyway (I bought my DS7 before the WiFi-only model was available).
And I agree that nvflash may be overused, but I am not a fan of CLI (adb, etc.) - too easy to make one little mistake.