Feanor

Like everybody on MyOpera knows, thanks to the message "from above", Opera 10 (the browser) is out. My opinion is the same as usual. Opera is good software, a very good browser with lots of nice options for customizing and an integrated advanced mail client. I would suggest Opera to anybody but in the same time I can't find a reason to prefer Opera over Firefox that is my first option.
Opera 10 was meant to have two major "innovations".
One is the "Turbo" feature for slow speed Internet connections. It works by connecting to a proxy server operated by Opera (the firm) that caches the Web pages and compress them before sending to you, especially images, to reduce the amount of data transferred. Like I said before, this was a common trick in the '90s when many people had dial-up connections.
The other feature is "Unite" but it did not make it to Opera 10 yet, it is still under development. Unite is a webserver that you run on your computer and allows other people to connect to you to browse your pictures or download files. To find other people you can use either their IP address or search among registered users over Opera (the firm) community. It was introduced as "revolutionary" but I can't understand why. Of course it makes it easier for anybody to run a webserver but the concept in itself is not exactly new. And you know, running a server over a personal computer is not always a smart idea, basically because personal computers are not meant to be online 24/7, neither "safe" as servers. When I switch my computer off, my images collection is offline and my friends from Australia can't access it. When my hard disk crashes the collection is lost because I don't do any backup, etc.

I use Opera (the browser) and I have insisted for years when developing sites in order to make them support Opera as well as other browsers. But I must admit Opera is not my primary browser since I am more a Firefox user. I am not a "fanboy" of any software then.
That said, I found this article that summarizes some of my doubt about "Unite" and adds some more. It is detailed and written much better than I ever could.

http://factoryjoe.com/blog/2009/06/16/thoughts-on-opera-unite/

My opinion is the issue here is not technical, being "Unite" a cool tool.
It is more about marketing, like I said in a previous post.
I get really annoyed by this sort of marketing tactics, especially when I don't see the need for it.

I am trying Opera 10 Beta and so far I can say:
1. the beta installer should create a new "group" in "programs" and a new icon on the desktop instead of overwriting the existing Opera 9x stuff. It is annoying but not catastrophic because fortunately it creates a new profile. Careful with the default settings.
2. the structure of the profile and subdirs is different from Opera 9.x. I don't know what happens if you merge the two.
3. it looks more responsive in heavy pages and JS than Opera 9.x.
4. the new default skin is much better than the old one, way less "heavy". It remembers a little of Chrome. I still don't like the grey-black colors and the omni-present gradient effect. The "panels" on the left look ugly.
5. there is an inline spell checker finally but it seems it doens't work too well because it stopped working while I was typing this.
6. the "turbo" mode is nothing new since proxies are as old as the Internet. I am not going to use it because I don't need a compressed Web and because the big issue about proxies, besides the bandwidth and hardware limitations, is the activity logging then privacy concerns.
7. the "visual tabs", that is a preview of the tab content you can have in an area on top of the browser, looks like a cool trick I won't ever use because it takes away too much screen space. You can have the preview the same with the mouse rolling over the tab.

You can have updates on Opera here: http://my.opera.com/desktopteam/blog/

Since it seems the devs re-introduced the "open new tab" button in Firefox 3.1, I am going to show you why I think Opera needs some redesign.

Edit: imagine updated to make a more fair comparaison. Thanks Tamil (see the comments). I've also marked the similar buttons you need to enable in both browsers.
Hoping they are not going to remove this feature, in Firefox I can see the tab bar only when there are at least two pages opened, instead of having it always visible and move the "bookmarks" out of their dedicated bar to any other bar, so I usually place them on top, then I don't need the browser bar any more. You can see Firefox adapts to the native looking of the operating system, in my case old Win2K. Opera instead has got FOUR oversize bars visible and a very intrusive default skin which I really dislike because of its darkness and because of the always present gradients that give it that "bumpy" look.

Yes, I know you can change the "skin" on both browsers. But this is another issue since there are very few good skins for Opera and almost none for Firefox.

Edit, maybe I was cryptic. People at Mozilla are worried about the users not understanding the "tabs", especially those moving from IE to FF, so they planned to make the tab bar ALWAYS visible, removing the preference and removing also the "open new tab" button in the "customize" panel, relying only on the "+" placed on the tab bar. This seems to have upset lots of people besides me and after months having all the nightly builds without the button (but retaining the option) we got it back in these last versions. On a side note, the good thing about FF is that right after the button removal somebody wrote an extension to add it back.

I've just discovered Google released some sort of "plugin" for adding voice and video calls capabilities to the GTalk feature embedded in the GMail page. The system requirements say "WindowsXP or later" but I guess there is a version for MAC, the supported browsers are FF 2.0+, IE 6.0+, Safari 3.0+, and Google Chrome.
http://mail.google.com/videochat

Opera is not supported.