If your Google Sitemap file is in "pending" status and you are worried that it will never come out of that status, I would not worry. Google recently posted an announcement that this is a known issue and they are working to resolve it.
The announcement was posted by Google's JohnMu:
Some new Sitemaps submitted via Webmaster Tools may remain in a "pending" state. We are aware of this issue and are looking into it; you do not need to take any action. This will have no effect on your site's performance in search results.
We have some worried webmasters, who I have notified not to worry. There are threads on this topic at WebmasterWorld and Google Webmaster Help, amongst others.
Like I said yesterday, Google Webmaster Tools is buggy, so don't let the bugs, um... bug you out (sorry, I had to).
Forum discussion at WebmasterWorld and Google Webmaster Help.
