Indexes And UniqueIdentifier Fields

I have a table that contains articles (as in, newspaper articles, blog
articles, whatever). I need to use a column of type uniqueidentifier
because one of the requirements is that I be able to write the articles
out to XML or import them from XML, and references (as in, "for more
info read this: 2323-232-90934" have to still work after the export and
import).

So as a minimum, the table is going to look like this:

CREATE TABLE Articles (
ArticleID uniqueidentifier,
PublishDate datetime,
Title nvarchar (50)
ArticleContent ntext
)
GO

ALTER TABLE Articles ADD
CONSTRAINT PK_Articles
PRIMARY KEY NONCLUSTERED (ArticleID)
WITH FILLFACTOR = 100
GO

As you can see, I'm not going to use a clustered index on a column of
type UniqueIdentifier. I got that much from this newsgroup and from
websites on sql server performance tuning.

Two questions. 1: I will obviously need to list recent articles. I'll
need to do: select top 10 ArticleID, PublishDate, Title from Articles
order by PublishDate desc

Will there be any problem with an index on a datetime field to make
that query faster?

CREATE UNIQUE CLUSTERED INDEX IX_Articles_PublishDate
ON Articles (PublishDate DESC)
WITH FILLFACTOR = 100
GO

Question 2: Is there anything else that I can do here that I'm missing?
Should I maybe also have a auto-increment field and put the clustered
index on it instead?

Thanks in advance
chris