Selected fixes since 1.0 PR2:
* Fixed: 252679 - Add EULA for Firefox.
* Fixed: Another round of icon updates.
* Fixed: 262688 - Bump version numbers to 1.0.
* Fixed: 267122 - Security hole.
* Fixed: 245770 - Backslash rendered as yen in japanese locale.
* Fixed: 267352 - Printing doesn't print form inputs.
* Fixed: 267854 - Parser data listeners don't get all the data in all cases.
* Fixed: 267648 - Upgraded from PR to RC2 through Sw update, lost "Help Content" and "For Internet Explorer Users" links.
* Fixed: 266511 - Import Wizard doesn't show what items were imported.
* Fixed: 180628 - Page setup dialog takes RTL where it shouldn't.
* Fixed: 253008 - Set network.proxy.share_proxy_settings if IE has a single proxy set up.
* Fixed: 267723 - ViewSource doesn't scroll to the selected line when opened from JS Console links; ViewSource->Edit->Go to Line broken as well; works in 1.0PR.
* Fixed: 267738 - Java plugin place-holder does not find Java plugin, plugin information bar works.
* Fixed: 266857 - Cannot print more than once with a printer with non-Latin1 (e.g. Japanese) characters in its name.
* Fixed: 255196 - DDE: Request WWW_OpenURL send to Mozilla web page address without last character of address.
* Fixed: 256111 - Customize toolbar bottom items are partly covered by horizontal scrollbar if size is not wide enough.
* Fixed: 266822 - Crash if right-clicking on a text box, wait for text box to go away, press escape [@ nsMenuListener::KeyPress]; affects find bar in Firefox.
* Fixed: 267797 - Crash with gmail.com.
* Fixed: 267249 - Crash when clicking on link in pop-up window.
* Fixed: 267804 - Crash blocking iframes with AdBlock extension.
* Fixed: 267919 - Crash if Adobe SVG plugin is not installed.
* Fixed: 236343 - [Mac] Full screen mode shows Windows-like minimize/maximize/close buttons.
* Fixed: 205974 - [Mac] Missing PrintPDE.plugin: can't print background colors, selection or frames.
* Fixed: Add to credits: Jeff Walden, Luke Stone, Mitchell Baker, Chris Beard.
Also since RC1:
* Fixed: Add creative commons search plugin to default set.
* Fixed: Updated Firefox icon. 32x32 is brighter, 16x16 is darker and higher-contrast.
* Fixed: 266554 - No referrer sent for meta refresh.
* Fixed: 264560 - Security hole.
* Fixed: 267263 - Security hole.
* Fixed: 267244 - Ensure Locales all use correct tracking params for Yahoo/Google.
* Fixed: 266292 - Strange behaviour with command line, or even sometimes crash, when using gtk handled arguments.
* Fixed: 267367 - Image loading from chrome results in auth prompts if src is protected.
* Fixed: Add to credits: Namachivayam Thirumazhusai (shiva), Doron Rosenberg, Peter van der Woude (peter6), Jonathan Granrose, Chase Phillips
* Fixed: [Mac] Many changes to Pinstripe (default theme for Firefox on Mac)
* Fixed: 265371 - Crash when ISINDEX is used with position: fixed.
* Fixed: 266000 - Bookmarks toolbar folder links to firefox product page.
* Fixed: 266199 - Bump rv: version to 1.7.5.
* Fixed: 266954 - A few default bookmarks are missing titles.
* Fixed: 226602 - [Mac] Need Document Icons for Firefox.
* Fixed: 266777 - [Mac] Disable application update UI on Mac.
* Fixed: 246403 - Bad import bookmarks from Opera (non-ASCII characters garbled).
* Fixed: 266375 - Crash on restart of Firefox 1.0 RC1 after updating from Firefox 0.10.1.
* Fixed: 266457 - Remove "Firefox Crew's Pick list" from default bookmarks (subjectively appropriate links).
* Fixed: 266530 - Throbber should go to Firefox Central.
* Fixed: 266759 - Disable Single Window Mode pref UI by default for 1.0. (The prefs still work, and you can show UI for them using browser.tabs.showSingleWindowModePrefs.)
* Fixed: 262887 - Security: When a web page in a background tab shows a dialog, switch to that tab.
* Fixed: 265100 - "Sort by Name" in bookmarks-toolbar context menu, then typing in text field, causes crash.
* Fixed: 266346 - Popups enabled while javascript alerts() are open.
* Fixed: 257538 - Plug-in properties caches when called through DOM.
* Fixed: 262688 - Bump version numbers for 1.0 RC2.
* Fixed: 266776 - Incorrect window object returned by window.open if forced into same tab.
* Fixed: 263844 - Window.close() not working on new windows opened into tabs.
Anything marked 'Security hole' is worth the upgrade in my book, though most of them tend to be minor potential issues rather than full-blown exploits. Still, better safe than sorry.