This is strange, did you get locale and location settings after you typed your password?
Anyone else facing similar problem?

I selected my locale, region and then timezone, yes. After that there were yet a few other checks (white lines on black screen), that seem to go well too, and then this blinking underscore.

Uboot configuration seemed to work correctly too (I still have menu entries for Maemo, Maemo power-kernel, Bootmenu, and now Kali). I've tried launching the script from Maemo power-kernel first. But then I tried reinstalling (re-extracted the kali tar.gz, etc.) and tried configuring uboot from Maemo with vanilla kernel.

I've tried reinstalling, changing the locale, but no success. There is a third partition on my SD card, in FAT32, don't know if it can be related to the issue.

Quite similar to my experience. Here is a "screenshot" just before the blinking starts.

I also have three partitions: ext4 & 2*swap (for flopswap). Have to try again later with a different card. No SIM, but I assume this shouldn't make a difference.

May be something is wrong with the uploaded file. I'll check it once.

I have no sim either, but I don't see it making any difference. Hope this is indeed a problem with the upload and we'll have a solution soon!

It wasn't, at least for me. I got it running but don't really know what was the exact reason for failing before.

First, I erased & re-created the microSD's partition layout (ext4, swap, swap) with GParted (used Disks or sth like that earlier).

At booting Kali, I only chose the en_US.UTF-8 locale and set C.UTF-8 as default. Region and TZ as before. And hohum, the GUI started!
Afterwards, I ran dpkg-reconfigure locales as root and tested creating & setting the default locale to something else and after reboot it also worked. Finally, I set the default to en_US.UTF-8.

Beyond re-creating the uSD layout and using different locales nothing else changed for me, didn't even re-download the kali image.

(Later on, I've had some small problems to overcome like adding the user to the netdev group to get wicd running and NetworkManager still isn't running as user, only when logged in as root, but these are an another matter)

I also booted to Maemo for a while to see that FlopSwap works and then booted back to Kali so my guess is the 3 partitions shouldn't be a problem.

TL;DR: The uploaded image is probably fine. Try with a re-created partitioning or another uSD card. If all else fails, try different default locales.
EDIT: I only now noticed that Kabouik had already tried different locales without success, so maybe the locales can be ruled out.

Yes, I tried different locales too, but might give it another try with the same you succeeded with. [Edit: still not working.]

I also had recreated the µSD's partition layout and reinstalled, but no success. I now have 5 partitions though (did not know about Flopswap, so your previous post convinced me into trying it, which ended up in adding new partitions), so I wouldn't say that I made it simpler. The partitions are Ext4 for Kali, Ext4 for EasyDebian, FAT32 for storage, Swap, Swap. Patitions were created in gparted too.

Did you by any chance use "tar" without "sudo" for extraction the second time? I might give it a try as user, just in case.

Comp... Command line history says 'no'.
Sorry, I couldn't help you more. I hope you get it working, eventually!

Ah! I configured it again with the en_US.UTF-8 and had no success. I rebooted in Maemo to connect the µSD to my computer in storage mode, and did a "sudo chmod -R 777 ." in /media/KaliN900 (where the corresponding partition is mounted on my computer). I rebooted the phone, launched Kali N900 again, was not asked to configure anything, and now I have an UI and can enter my username and password!

I doubt what I did is safe though, but it might help pinpointing the issue. Any advice would be welcome. Turns out I might have broken sudo by doing that, among other things.

(And I have the same Netdev issue as you.)

Yes. You set wrong permissions on several files by that.
Sudo and sudoers files being two.
The correct permissions for these two, as an example, would be.

Some will need other.