Yes, I do plan to speak about other stuff, don't worry. This isn't a Windows 10 blog, but a series :P
One of the most bizarre/interesting features is Cortana, "your personal assistant". I decided to release some of my data to Microsoft so that I can enable it - yes, you have to. It's hardcoded to force you to allow it to read your data, which is.. well, dangerous. Or isn't it? Anyway, I enabled it and decided to give it a try.
First thing I tried was "What does the fox say?" (answer here), just for the joke. This is really awesome! I still laugh at it, it's simply really well done. But that's as far as it goes. Yes, it can tell a joke, a story, sing a song and even tell you that 42 is the answer to everything. I don't have an iPhone, but from the videos I see online, Siri is way better at parsing what I say and answering useful stuff. Cortana is more like S Voice from Samsung: sure, it has some features that might be useful, such as reminders and notes, but that's it. It doesn't really understand what you say, at least from my tests.
Cortana seems to be designed as a simple tool, at least right now. I'm pretty sure they're improving it, but it doesn't understand some pretty simple sentences, such as "call me John" (it tries to call John). But if you ask it your name, it'll answer the name you set on the initial setup. As far as I could test, you can't tell Cortana to change it - not like that. I think it's lacking a lot of cool stuff on its parser. But regarding the tool side of it, well... I couldn't even make it take a picture of me! Seriously, how hard is it to understand "take a picture"? Or "take a photo"? Or even "camera"?! Come on, Microsoft! What do I have to say so that Cortana will open the Camera app and take a picture?
Quick note on the "call me John": as Marcus pointed out, it would be an issue if the user said "call me an ambulance". But I think this is more a grammar issue than a parsing issue: "call me X" is for defining a name, while "call X" and "call me a[n] X" is for calling people or services.
Oh, and before I forget: everytime it doesn't understand you, it opens Bing with your sentence. Like that's gonna help at all. I couldn't find a way of disabling it, even though I can disable for system search. When Cortana is enabled, you don't have access to that option anymore - at least I couldn't find it. :-(
But hey, we have reminders! I said "Hey Cortana, remind me to clean in five minutes", and it added the reminder, which worked pretty well. Except you can snooze or close the reminder through it: you have to go there and click on the reminder. I even tried "clear my schedule", but it only understood "schedule". And yes, it does tell you your schedule, and even the weather for tomorrow (in Fahrenheit ...) if you ask for it. You can even ask it to play some music, loading it from your library. Of course it couldn't load anything from mine: I didn't configure anything on Windows to allow it find my almost 100GB of songs, so...
Quick note: I ask it once if it could speak German, just for fun. The answer was "In Germany, ja". Except that if you change your region to Germany, it says that Cortana isn't available. Ha, funny. And no, you can't ask it to translate something from German to English: it doesn't really understand "können wir auf Deutsch sprechen?"... :-(
I just said you can ask Cortana about your schedule for tomorrow. Yes, you can, but you need to fill the Calendar app with data (aka appointments) for that. So yes, it does need access to your calendar... and your location (it has to be USA, otherwise it doesn't work..?!), your texts (it's a desktop computer for god's sake), your microphone (fair enough, I want to talk to it), your speach/ink/whatever recognition (sure) and some other random stuff. So yes, it needs to read your data, parse it (maybe on Microsoft servers?) and then it'll be ready to help you. But you don't want to give your data so easily to Microsoft, do you?
Everyone is really scared about the privacy issue that Windows 10 brought on its free, traffic-hungry, scary update. Data, so much data, being analyzed by Microsoft, who people won't trust at all, but keep to use their OS. But you trust Google (or Apple), right? Almost everyone with an Android phone has a Google account on it. That account is used for synchronization, by default, of your contacts, agenda, apps, email (Gmail), files (Drive), photos, social network (Google+), personal details (no idea), tasks, and so on. So let me see if I got this straight: you are ok with giving Google your data, but not Microsoft? Why? And yes, Apple also captures/sync your data, but I can't really talk about it until I get my hands on an iPhone for a few hours/days/weeks/lifetime.
So to everyone who syncs their Android phone data with Google servers: why are you so scared of releasing your data to Microsoft? You can add your Google account to Windows 10 (afaik) and have the calendar load your schedule, the same one you gave Google the right to read and parse. That way you can ask Cortana what's your schedule for tomorrow, add reminders, etc. So, what's so bad about it? Is it the way they're going to use your information? Do you even know how Google uses your data?!
I partially changed my opinion regarding privacy issues on Windows 10 after reflecting how much information I already give Google (yes, I sync my phone with their servers, I don't really care). Let's speculate: if NSA has access to Google or Microsoft, you're going to be screwed anyway, maybe even added to their no-fly or cyberterrorist list. It doesn't matter who has your data: if someone has it, they can use it for whatever they want as long as you allow the data to be with them. And, nowadays, if you want to use something new, like Google Now, Cortana or Siri, you have to provide your data, no matter how scared of it you are.